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FERTILIZERS 


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FERTILIZERS 


THE    SOURCE,   CHARACTER    AND    COMPOSITION    OP 

NATURAL,  HOME-MADE  AND   MANUFACTURED   FERTILIZERS 

AND   SUGGESTIONS  AS  TO  THEIR 

USE   FOR  DIFFERENT  CROPS  AND   CONDITIONS 


BY 

EDWARD    B.  VOORHEES,  A.M. 

Director  of  the  New  Jersey  Agricultural  Experiment  Stations,  and 
Professor  of  Agriculture  in  Rutgers  College 


FOUBTH  EDITION 


THE    MACMILLAN    COMPANY 

LONDON:    MACMILLAN  &   CO.,  Ltd. 

1902 

All  rights  reserved 


COPYBIGHT     1898 

Bt  EDWARD   B.  VOORHEES 


Set  up  and  electrotyped  November,  1898 

Reprinted  with   corrections   January,  1900 

January  and  February,  1902 


SOount    i^Ieaisant    J&te»» 

J.  HOBACK    McFARLAND   COMPANT 
HaRRISBITEG   •  PEyNSYLVANIA 


. PREFACE 

There  is  no  question  as  to  the  desirability  of 
the  use  of  commercial  fertilizers  on  most  farms, 
though  the  methods  now  generally  practiced  are  such 
as  to  indicate  the  very  great  need  of  a  better  under- 
standing of  what  the  functions  of  a  fertilizer  are, 
of  the  terms  used  to  express  their  composition  and 
value,  of  the  kind  that  shall  be  used,  and  the  time 
and  method  of  application  for  the  different  crops 
under  the   varjdng   conditions  that   exist. 

In  the  preparation  of  this  book,  therefore,  it  has 
been  the  aim  of  the  author  to  point  out  the  under- 
lying principles  and  to  discuss,  in  the  light  of  our 
present  knowledge  of  the  subject,  some  of  the 
important  problems  connected  with  the  use  of  fer- 
tilizer materials.  The  subject  is  a  large  one  when 
considered  in  all  its  bearings,  and  much  must  nec- 
essarily be  omitted  in  a  book  intended  for  the 
general   reader  as   well   as  the   student. 

The  author  appreciates  keenly  his  limitations, 
owing  to  the  lack  of  definite  knowledge  on  many 
vital    points ;    yet    it  seems   that   at   this    time,    when 

Cv) 


VI  PBS  FA  CIS 

the  investigations  of  the  experiment  stations  are 
beginning  to  be  regarded  as  important  educational 
factors,  and  when  these  institutions  are  more  than 
ever  prepared  to  study  the  fundamental  principles 
which  underlie  the  various  processes  involved  in 
plant  nutrition,  the  practical  man  should  have  a 
clear  understanding  of  what  is  now  known,  in  order 
that  he  may  be  prepared  to  accept  and  use  that 
better  knowledge  which  will  undoubtedly  be  pro- 
vided  for   him   in   the   near   future. 

E.  B.  V. 

New  Bkunswick,  N.  J..  September  20,  1898. 


CONTENTS 

CHAPTER   I 

PAGKS 

The  Natural  Fertility  op  the  Soil,  and  Sources  of 

Loss  OF  the  Elements  of  Fertility  1-20 

Soil  Fertility— Chemical  elements  needed  in  plant 
growth— Fertility  as  influenced  by  water,  climate  and 
season  — The  influence  of  physical  character  of  soil- 
Location  of  soil  qualifies  the  term  "  fertility  "— Practical 
fertility  is  usable  potential  fertility    2-7 

What  Becomes  op  Our  Fertility  ? 7-8 

Sources  of  Natural  Loss  of  Nitrogen— Importance  of 
careful  culture— Loss  of  nitrogen  by  drainage— Escape  of 
nitrogen  into  the  atmosphere 8-12 

The  Natural  Loss  of  the  Mineral  Elements— Losses 
due  to  mechanical  means 12-14 

Artificial  Losses  op  Fertility— A  comparison  of  the 
prices  received  for  the  fertility  elements  in  different 
crops  — Fertility  content  of  cereals  and  vegetables— Irra- 
tional farm  practice  — Losses  in  manures 14-20 


CHAPTER    II 

The  Function  of  Manures  and  Fertilizers,  and  the 

Need  of  Artificial  Fertilizers   21-37 

The  Essential  Elements  of  Fertilizers 21 

Natural  Manures  and  Artificial  Fertilizers 22 

(vii) 


Vlll  CONTENTS 

PAGES 

Direct  and  Indirect  Effect  of  Manures 23 

Unavailable  and  Available  Plant-food  24-26 

Danoer  of  Loss  from  the  Use  of  Soluble  Plant-food..  26 
The  Usefulness  of  a  Fertilizer  Constituent  Does  not 

Depend  Upon  Its  Original  Source 27 

Use  of  Fertilizers 28,  29 

The  Need  of  Artificial^  Fertilizers— The  cost  of  produc- 
tion per  unit  of  income  is  increased— A  f^reater  demand  for 
special  crops  — Farm  manures  are  inadequate— The  growing 
importance  of  fruit-growing 30-35 

Will  It  Pay  to  Use  Fertilizers? 35-37 


CHAPTER   III 

NiTROGENpus  Fertilizers  38-57 

What  Is  Meant  by  Form  of  Nitrogen  1 39 

Dried  Blood 40,  41 

Dried   Meaj   or   Meal,    Azotin,  Ammonite,   or   Animal 

Matter 41 

Hoof  Meal 42 

Dried  and  Ground  Fish,  or  Fish  Guano 42 

King  Crab 43 

Tankage 43,  44 

Garbage  Tankage 44 

Low-grade    Nitrogenous    Products -Leather  meal  — Wool 

and  hair  waste 45 

Vegetable     Nitrogenous    Products— Cotton-seed    meal  — 

Linseed  meal—  Castor  pomace 40 

Natural  Guanos 47-49 

Ammonia  Compounds  — Sulfate  of  ammonia 50,  51 

Nitrate  Nitrogen— Nitrate  of  soda 52 

The  Relative  Availability  of  the  Different  Forms  of 

Nitrogen— Conditions  which  modify  availability 53-57 


CONTEXTS  IX 


CHAPTER   IV 


PAGES 


Phosphates— Their  Sources,  Composition,  and  Rela- 
tive Value 58-77 

Phosphate  of  Lime,  or  Bone  Phosphate— Animal  Bone— 
Raw   bone  — Fine  bone— Boiled  and   steamed  bone  — Bone 
tankage— Other   organic   products  — Bone-black,   or  animal 
charcoal— Bone  ash 59-66 

Mineral  Phosphates— South  Carolina  rock  phosphates- 
Florida  phosphates  — Canadian  apatite --Tennessee  phos- 
phate—Iron phosphate,  or  Tliomas  phosphate  powder— 
Phosphatic  guanos 66-71 

Phosphates  as  Sources  of  Phosphoric  Acid  to  Plants— 
The  influence  of  source  of  phosphate  upon  availability — 
Influence  of  fineness  of  division  — The  character  of  soil  as 
a  factor  influencing  availability— Influence  of  kind  of 
crop  — General  considerations 71-77 


CHAPTER   V 

Superphosphates— Potash 78-98 

Insoluble  Phosphoric  Acid , 78 

Soluble  Phosphoric  Acid 79 

Reverted  Phosphoric  Acid 80 

How  Superphosphates  are  Made  — The  difference  in  the 
superphosphates  made  from  the  different  materials  — Sol- 
uble  phosphoric  acid  identical  chemically,  from  whatever 

source  derived  80-83 

Phosphates  and  Superphosphates  are  not  Identical...        83-87 

Double    Superphosphates 87 

Chemical  Composition  of  Superphosphates  — Well-made 
superphosphates    contain    no  free    acid  — Phosphoric    acid 

remains  in   the  soil  until  taken  out  by  plants 88-91 

Potash  Salts— The  importance  of  potash  as  a  constituent 
of  fertilizers— Forms  of  potash  — Kainit—Sylvinit— Muri- 
ate of  potash  — High-grade  sulfate  of  potash  — Double 
sulfate  of  potash  and  magnesia— Fixation  of  potash 92-98 


X  CONTENTS 

CHAPTER    VI 

PAGES 

MiSCELLAKEOUS    PERTILIZINa    MATERIALS       99-123 

Tobacco  Stems  and  Stalks 100,  101 

Crude  Fish  Scrap 101-103 

Wool  and  Hair  Waste 103 

Poultry  and  Pigeon  Manures 104 

Sewage 105 

Muck  and  Peat 106 

King  Crab,  Mussels  and  Lobster  Shells 107 

Seaweed 108 

Wood  Ashes  and  Tan-bark  Ashes 109-111 

Coal  Ashes Ill 

Cotton-hull  Ashes  Ill 

Marl   112 

Lime 113-116 

Agricultural  Salt 116 

Powder  Waste 117 

Green  Manures— "Nitrogen  gatherers  "  and  "nitrogen  con- 
sumers"—The  most  useful  crops— Green  manure  crops  that 

consume  the  nitrogen  ii;  the  soil   11 7-123 

CHAPTER    Vn 

Pcrchase  of   Fertilizers     124-148 

Standard   High-grade  Materials 125,  126 

Fertilizing  Materials  Variable  in  Composition 126,  127 

High-grade  and  Low-grade  Fertilizers  — The  "unit" 
basis  of  purchase— The  "ton"  basis  of  purchase — The 
necessity  of  a  guarantee  — Laws  alone  do  not  fully  protect— 
Method  of  statement  of  guarantee  sometimes  misleading- 
Discussion  of  guarantees  — The  advantages  and  disadvan- 
tages of  purchasing  raw  materials  and  mixed  fertilizers . . .  127-141 
Home  Mixtures  — Formulas— A  low-grade  fertilizer— The  cost 

of  handling  "  make-weight " 141-147 

General  Advice 147-148 


CONTENTS  XI 

CHAPTER    VIII 

PAOXS 

Chemical  Analyses   of  Fertilizers 149-166 

The  Interpretation  of  an  Analysis 149-152 

The  Agricultural  Value  of  a  Fertilizer 152-153 

The  Commercial    Value    of    a    Fertilizer— Schedule    of 

trade  values  adopted  by  experiment  stations  for  1898 153-162 

Calculation  of  Commercial  Values 162-164 

The  Uniformitz  of  Manufactured  Brands *. .  164-166 

CHAPTER   IX 
Methods  of  Use  o*'  Fertilizers 167-190 

Conditions  Which  Modify  the  Usefulness  of  Fer- 
tilizers—Derivation  of  soil  a  guide  as  to  its  possible 
deficiencies- Physical  imperfections  of  sandy  soils— Physi- 
cal imperfections  of  clay  soils  — The  influence  of  previous 
treatment  and  cropping— The  influence  of  character  of 
crop— The  kind  of  fanning,  whether  "extensive"  or 
"intensive  " 167-177 

Plants  Vary  in  Their  Power  of  Acquiring  Food— Char- 
acteristics of  the  cereal  group— Characteristics  of  grasses 
and  clovers— Root  crops— Market-garden  crops— Fruit 
crops 177-182 

Systems  of  Fertilizing  Suggested— A  system  based  upon 
the  specific  influence  of  a  single  element— A  system  based 
upon  the  necessity  of  an  abundant  supply  of  the  min- 
erals—A system  based  on  the  needs  of  the  plants  for  the 
different  elements  as  shown  by  chemical  analysis  — A 
system  in  which  the  fertilizer  is  applied  to  the  "money 
orop"  in  the  rotation— An  irrational  system 182-190 

Summary 190 

CHAPTER   X 

Fertilizers  for  Cereals  and  Grasses    191-213 

Experiments  to  Determine  the  Lacking  Element— A 
scheme  for  plot  experiments— Results  that  maybe  attained.     193-198 


XU  CONTENTS 

PAGES 

The  Importance  of  System  in  the  Use  op  Fertilizers— 
Indian  corn  exhaustive  of  the.  fertility  elements  — Oats- 
Wheat— Clover— Timothy— A  gain  of  fertility  by  the  sys- 
tem—The necessity  of  adding  more  plant-food  than  is 
required  by  a  definite  increase  in  crop  — The  system  should 

be  modified  if  no  farm  manures  are  used 198-207 

Fertilizers  for  a  Single  Crop  Grown  Continuously  . . .     208-211 

Fertilizers  for  Meadows 211 

Will  Thjs  System  OF  Fertilizing  Pay? 212,213 

CHAPTER   XI 

Potatoes,  Sweet  Potatoes,  Tomatoes  and  Sugar  Beets    214-240 

Fertilizers  for  Potatoes,  Early  Crop— The  time  and 
method  of  application— The  amount  to  be  applied  —  Form  of 
the  constituents 215-220 

Late  Potatoes 220,  221 

Sweet  Potatoes— Fertilizer  constituents  contained  in  an 
average  crop  — The  application  of  fertilizers 221,  226 

Tomatoes— Field  experiments  with  fertilizers  for  tomatoes- 
Fertilizers  for  the  early  crop  for  different  conditions  of 
soil— The  use  of  fertilizers  with  yard  manures  — Fertilizers 
for  lato  tomatoes 226-235 

Sugar  Beets  — The  demands  of  the  crop  for  plant-food  — The 
influence  of  previous  deep  cultivation  of  soil 235-240 

CHAPTER   XII 
Green  Forage  Crops  241-261 

Maize  (corn)  forage— Silage  corn— Wheat  and  rye  forage- 
Spring  rye— Oats— Oats  and  peas— Barley  and  peas  -Millet. 

Clovers  and  Other  Legumes— Cow  pea  and  soy  bean- 
Alfalfa,  or  Lucerne— Need  of  lime  for  legumes  — Scheme  of 
soiling  crops 249-257 

Root  Crops— Fertilizers  for  fodder  beets,  sugar  beets  and 
carrots  — Turnips,  Swedes  and  rape 257-261 

Tuber  Crops 261 


CONTENTS  Xlll 
CHAPTER    XIII 

PAGES 

Market-garden   Crops    • 262-281 

The  Yield  and  Quality  Dependent    upon    Continuous 

AND  Rapid  Growth 262-264 

Asparagus— The  use   of   salt— Fertilizers  that  have  proved 

useful— A  basic  fertilizer  for  market  garden  crops 264-269 

Peas  and  Beans 269,  270 

Beets  and  Turnips 270-272 

Cabbage,  Cauliflower  and  Brussels  Sprouts 272,  273 

Cucumbers,   Watermelons,    Muskmelons,   Pumpkins  and 

Squashes  273-275 

Celery    275 

Sweet  Corn 276 

Egg-plant,  Spinach,  Lettuce  and  Rhubarb  277-278 

Onions,  Onion  Sets  and  Scallions 278-281 

CHAPTER   XIV 

Orchard  Fruits  and  Berries 282-304 

Fruit  Crops  Differ  from  General  Farm  Crops 283 

The   Specific   Functions  of  the  Essential  Fertilizing 

Constituents 284 

The  Character  of  Soil  an  Important  Consideration...  285-287 

The  General  Character  of  the  Fertilization 287,288 

The  Application  of  Fertilizers  for  Fruits 289 

The  Fertilization  of   Apples  and    Pears— The  amounts 

to  be  applied     289-294 

Peaches  — The  need  of  fertilizers  — Methods  of  fertilization..  294-299 

Plums,  Cherries  and  Apricots 299 

Citrous  Fruits 299 

Small  Fruits  in  General  300 

Strawberries 301 

Raspberries  and  Blackberries 302 


XIV  CONTIINT8 

PAOKS 

cubrants  and  goosebekries 303 

Grapes 303,  304 


CHAPTER   XV 

Fertilizers  for  Various  Special  Crops 305-327 

Cotton— Fertilizers  for  cotton  — Formulas  for  cotton  ferti- 
lizers-Method ol:  application    305-312 

Tobacco— The  influence  of  fertilizers  upon  the  quality  of 
the  crop— The  conclusions  from  Connecticut  experi- 
ments—Form of  the  constituents— Amounts  to  apply 312-317 

Sugar-Cane  — The  needs  of  the  plant  as  indicated  by  the 
Louisiana  experiments— The  application  of  fertilizers  ....     317-321 

Miscellaneous  Crops—  Sorghum  —  Buckwheat—  Peanut- 
Roses  and  other  flowering  plants— Lawn  grasses- 
Forcing-house  crops 321-327 


FERTILIZERS 


CHAPTER  I 


NATURAL  FERTILITY  OF  THE   SOIL,  AND   SOURCES 
OF  LOSS  OF  THE   ELEMENTS  OF  FERTILITY 

There  is  no  one  question  of  greater  importance  to 
the  farming  industry  than  that  of  soil  fertility.  In 
order  that  the  industry  may  be  successful,  it  is  not 
enough  to  produce  crops  ;  it  is  necessary  that  their 
production  shall  result  in  a  genuine  profit.  That  is,  it 
is  not  enough  to  produce  crops  which  bring  more  than 
they  cost  in  the  way  of  labor  and  manures,  without 
taking  into  consideration  the  effect  of  their  growth 
upon  the  future  productive  capacity  of  the  soil.  The 
relation  of  the  outgo  and  income  of  the  fertility  ele- 
ments is  an  important  factor  in  determining  profits, 
and  must  be  considered.  The  farmer  who  secures 
crops  that  bring  more  than  they  cost,  and  who,  at  the 
same  time,  maintains  or  even  increases  the  productive 
capacity  of  his  soil,  is,  other  things  being  equal,  the 
broadly  successful  farmer.  Many  farmers  are  able  to 
accomplish  this  object  because  of  the  knowledge  they 
have  acquired  through  long  years  of  experience,  rather 
than  because  they  possessed  in  the  beginning  of  their 
work  a  definite  knowledge  of  the  fundamental  princi- 

A  (1) 


2  FERTILIZEBS 

pies  involved  in  crop  production,  and  upon  the  ob- 
servance of  which  their  success  depended.  One  of 
the  first  needs,  therefore,  in  the  use  of  commercial 
fertilizers  is  a  more  or  less  definite  knowledge  of  what 
constitutes  fertility,  and  of  the  principles  which  under- 
lie crop  production. 

SOIL    FERTILITY 

The  full  meaning  of  the  term  "soil  fertility"  is  not 
easily  expressed,  since  many  conditions  are  involved, 
all  of  which  exercise  more  or  less  influence.  The  po- 
tential fertility,  which  is  measured  by  the  total  content 
of  the  food  elements  contained  in  a  soil,  is  made 
practicable,  or  usable,  in  proportion  as  the  conditions 
are  favorable.  The  more  important  of  these  influenc- 
ing conditions  are  here  briefly  discussed.  In  the  first 
place,  it  is  of  the  utmost  importance  that  a  soil  should 
contain  those  elements  found  in  the  plant ;  hence,  it  is 
almost  self-evident  that  a  fertile  soil  must  contain  a 
maximum  quantity  of  those  particular  elements  or 
constituents  which  are  removed  from  the  land  in 
maximum  amounts  by  the  crops  grown.  The  removal 
of  crops  rapidly  exhausts  the  soil  of  these  elements, 
and  finally  reduces  the  quantity  contained  in  the  soil  to 
so  low  a  point  as  to  make  profitable  cropping  impossible. 

Chemical  Elements  Needed  in  Plant  Growth 

Careful  studies  and  experiments  have  shown  that 
plants  actually  take  from  the  soil  at  least  ten  chem- 
ical   elements    which    are   required    for    their    normal 


THE    CHEMICAL   ELEMENTS   NEEDED  3 

growth  and  development:  viz.,  nitrogen,  potassium, 
phosphorus,  magnesium,  sulfur,  sodium,  iron,  chlorin, 
silicon  and  calcium.  Yet  the  number  liable  to  rapid 
exhaustion  is  limited  in  many  cases  to  three,  and  at 
most  to  four,  which  are,  nitrogen,  phosphoric  acid 
(phosphorus),  potash  (potassium),  and  lime  (calcium), 
the  latter  only  in  exceptional  cases.  These  are  liable 
to  be  exhausted  because  they  exist  in  larger  amounts 
than  the  others  in  the  plants  that  are  grown,  and  in 
smaller  amounts  than  the  others  in  even  the  most  fer- 
tile soils.  It  has  also  been  proved  that  it  is  the  one 
element  of  these  which  exists  in  the  smallest  amount 
which  measures  the  crop -producing  power,  or  fertility, 
in  this  respect,  as  one  element  cannot  substitute  or 
exert  the  full  functions  of  another.  That  is,  there 
may  be  a  relative  abundance  in  the  soil  of  potash  and 
of  phosphoric  acid,  but  practically  no  nitrogen,  in 
which  case  good  crops  of  cereals,  for  instance,  could 
not  be  grown,  because  no  other  element  can  substitute 
the  nitrogen  required  by  the  plant,  and  it  can  be 
obtained  by  it  from  no  other  source  than  the  soil ;  and 
the  soil,  for  all  practical  purposes,  is  quite  as  unpro- 
ductive, lacking  in  productive  fertility,  as  it  would  be 
if  it  contained  much  smaller  amounts  of  the  mineral 
elements  mentioned,  and  thus  be  poorer  in  potential 
fertility. 

Fertility  as  Influenced  by  Water,  Climate  and 
Season 

In  the  second  place,  there  are  soils  that  are  so  rich 
in  all  of  these  elements  that  if  productiveness  depended 


4  FERTILIZERS 

upon  them  alone,  maximum  crops  might  be  grown  for 
centuries  without  exhausting  them,  while  actually  they 
are  now  incapable  of  producing  a  single  profitable  crop 
of  cereals,  grasses,  fruits,  or  other  products  of  the  farm, 
because  certain  other  conditions  which  are  essential,  in 
order  to  bring  them  into  activity,  are  absent.  For 
example,  it  may  be  that  water,  which  is  absolutely 
essential  both  for  the  solution  of  these  food  elements 
in  the  soil,  as  well  as  for  their  distribution  in  the  plant 
after  they  have  been  acquired,  cannot  be  obtained,  or 
that  the  temperature  of  the  soil  and  of  the  surrounding 
air  is  either  too  low  or  too  high,  thus  preventing  or 
interrupting  the  progress  of  those  changes  which  must 
go  on,  both  in  the  soil  and  in  the  plant,  in  order  that 
normal  growth  and  development  may  be  accomplished. 
With  a  full  supply  of  the  fertility  elements  in  the  soil, 
the  climatic  and  seasonal  conditions  exert  an  important 
influence  upon  its  productive  power. 

It  is  evident,  therefore,  that  the  chemical  elements 
of  fertility  in  themselves  are  not  sufficient  to  constitute 
what  we  understand  by  the  term.  Fertility  is-  not 
measured  by  them  alone ;  associated  with  them  there 
must  be  other  conditions.  That  is,  while  crops  cannot 
be  grown  without  these  elements,  it  is  the  conditions 
which  surround  them  that,  in  a  large  degree,  deter- 
mine the  power  of  the  crop  to  secure  them. 

The  Influence  of  Physical  Character  of  Soil 

In  the  third  place,  the  physical  character  of  a  soil 
is  also  a  factor  in  determining  actual  fertility.     This 


LOCATION  QUALIFIES  FERTILITY  5 

has  reference,  first,  to  the  original  character  of  the 
rocks  from  which  the  soil  particles  were  derived, 
whether  hard  and  dense  in  their  mineral  character,  thus 
resisting  the  penetration  and  the  solvent  effect  of  air 
and  water  and  other  agencies,  or  whether  soft  and 
friable,  and  freely  permitting  their  entrance  and  ac- 
tion ;  and  secondly,  whether,  in  the  formation  of  the 
soil,  the  particles  were  so  fine  and  so  free  from  vege- 
table matter  as  to  settle  in  hard  and  compact  masses, 
impervious  to  water,  air  and  warmth ;  or  whether  they 
were  coarse,  and  not  capable  of  close  compaction,  thus 
giving  rise  to  an  open  and  friable  soil,  freely  admit- 
ting the  active  natural  agencies,  such  as  we  find  to  be 
the  case  in  sandy  soils.  In  addition  to  these  properties 
of  soils,  which  have  a  distinct  place  in  determining 
fertility,  there  are  many  other  minor  ones  which  to- 
gether constitute  what  is  understood  as  "condition." 

location  of  Soil  Qualifies  the  Term  ^^ Fertility" 

Furthermore,  fertility,  even  in  this  true  sense,  may 
be  useless  because  of  the  location  of  the  soil  which 
possesses  it.  For  example,  there  are  many  places  on 
this  continent  where  sugar -producing  plants  will  grow 
and  develop  perfectly,  since  the  soils  are  very  rich 
in  the  fertility  elements,  and  since  the  surrounding 
conditions  are  most  favorable  for  their  culture,  yet, 
because  of  their  location,  it  is  unprofitable  to  grow 
them  for  the  manufacture  of  sugar.  In  the  first 
place,  the  soils  are  so  situated  as  to  make  it  impos- 
sible, or  at  least  impracticable,  to    provide  the  means 


6  FERTILIZERS 

necessary  for  converting  the  sugar -producing  crop 
into  actual  sugar,  and,  in  the  second  place,  even  it* 
it  were  possible  to  do  so,  the  great  distance  from 
shipping  stations  to  markets  so  increases  the  cost  of 
transportation  as  to  make  it  unprofitable  to  compete 
in  the  market  with  the  crops  grown  upon  lands  pos- 
sessing true  fertility  in  a  lower  degree. 

Practical  Fertility  is  Usable  Potential  Fertility 

Practical  fertility  is,  therefore,  dependent  upon 
many  conditions,  and  fortunately  our  own  country 
possesses  it  in  a  marked  degree ;  that  is,  the  utility 
of  the  potential  fertility,  as  represented  by  the  total 
mineral  content  of  our  soil,  is  such  as  to  make  us 
one  of  the  greatest  agricultural  nations  in  the  world, 
both  in  the  quantity  and  variety  of  products  grown. 
Our  soils  possess  the  essential  elements  in  lavish 
amounts,  and  our  climatic  and  seasonal  conditions 
are  such  as  to  permit  of  their  ready  conversion  into 
a  wide  series  of  valuable  products,  and  our  location 
and  facilities  for  handling  and  distributing  our  staple 
crops  are  such  as  to  enable  us  to  compete  in  any 
market  of  similar  commodities. 

Notwithstanding  the  truth  of  this  general  state- 
ment, it  is  also  true  that  in  certain  sections  of  our 
country  profitable  crops  cannot  be  grown  without  the 
addition  of  commercial  fertilizers,  because  the  soils 
are  either  naturally  poor,  or  they  have  become  par- 
tially exhausted  of  their  plant -food  elements.  That 
is,   the   amounts   that  become   available   to   the   plant 


WHAT  BECOMES   OF  FEBTILITT  7 

through  the  growing  season  are  not  sufficient  to 
enable  the  plant  to  reach  a  maximum  development, 
though  other  conditions  are  perfect. 

Our  future  progress  depends,  therefore,  upon  how 
well  we  understand  and  apply  the  principles  which 
are  involved,  both  in  the  conservation  and  use  of  the 
fertility  stored  up  in  our  soils,  and  in  the  use  of 
purchased  fertility ;  and  in  this  connection  it  is  im- 
portant to  consider  the  sources  of  loss  of  the  essential 
fertility  elements,  or  those  which  in  the  beginning 
measured  our  capabilities  in  crop  production, 

WHAT    BECOMES    OF    OUR    FERTILITY  ? 

Since  fertility  is  dependent  upon  so  many  con- 
ditions, or,  iu  other  words,  since  the  essential  elements 
of  fertility  are  dependent  upon  their  utility,  and  since, 
in  this  sense,  fertility  is  largely  determined  by  natural 
conditions,  it  is  pertinent  to  inquire,  first,  whether 
under  our  present  systems  of  management,  or  mis- 
management, of  the  land,  it  is  suffering  any  natural 
loss  of  fertility.  As  already  pointed  out,  the  most 
important  function  of  fertility  is  to  furnish  nitrogen, 
phosphoric  acid  and  potash,  and  since  the  content  of 
these  in  our  soil,  together  with  the  knowledge  we 
have  as  to  their  use,  measures,  in  a  sense,  our  pros- 
perity as  an  agricultural  people,  the  possibilities  of 
losing  them  from  the  soil  is  a  matter  of  national  con- 
cern, and  is  of  vital  interest  to  individual  farmers, 
who,  in  the  aggregate,  make  up  that  part  of  the 
nation  directly  affected  by  the  results  of  such  loss. 


8  FEBTILIZEBS 

It  would,  perhaps,  be  possible,  by  a  careful  chemical 
survey  of  our  soils,  to  determine  both  the  actual  and 
potential  fertility  of  our  entire  country,  and  this 
knowledge,  together  with  an  accurate  measure  of  the 
intelligence  exercised  in  its  use,  would  enable  a  predic- 
tion as  to  our  future  development,  if  present  methods 
were  continued.  That  is,  whether  our  land  would 
become  barren  and  worthless,  as  has  been  the  ease 
in  many  older  countries  which  at  one  time  were  quite 
as  productive,  or  whether  it  would  constantly  increase 
in  productiveness,  even  with  continuous  and  profitable 
cropping, — though,  as  already  pointed  out,  the  present 
barrenness  or  sterility  of  a  country  formerly  fertile 
may  not  be  due  entirely  either  to  the  natural  or  to 
the  artificial  loss  of  these  constituents. 

SOURCES    OF    NATURAL    LOSS    OF    NITROGEN 

Of  the  essential  constituent  elements,  nitrogen  is, 
in  one  sense,  of  the  greatest  importance;  first,  because 
it  is  the  one  that  is  more  liable  to  escape  than  the 
others,  and  secondly,  because  it  is  more  expensive  to 
supply  artificially  than  are  the  minerals.  It  is  the 
most  elusive  of  all  the  elements  :  to-day  it  may  be 
applied  to  the  soil,  to-morrow  it  may  be  carried  in 
streams  to  the  ocean.  It  is  also  unstable — which  is 
not  the  least  valuable  of  its  characteristics  if  properly 
understood; — to-day  it  is  an  element  of  the  atmos- 
phere, to-morrow  it  is  a  constituent  part  of  a  grow- 
ing plant,  the  next  day  the  same  element  may  exist  as 
an  animal   product,  and  the  day  following  it  may  be 


NATURAL   LOSS    OF    NITROGEN  9 

returned  to  the  soil  to  feed  the  plant.  It  is  more 
liable  to  escape  than  any  of  the  others,  because 
it  is  available  as  plant -food  largely  in  proportion 
as  it  changes  to  a  nitrate,  and  after  it  assumes 
that  form  it  is  seldom  absorbed  or  fixed  in  the 
soil.  Nitrogen  in  this  form  remains  freely  mov- 
able, and  the  probability  of  loss  by  leaching  is 
increased  in  direct  proportion  to  the  lack  of  preven- 
tive measures  used,  or  the  presence  of  those  conditions 
which  favor  leaching.  The  latter  may  be  classified  as 
follows:  First,  the  amount  and  time  of  the  rainfall; 
secondly,  the  absorptive  and  retentive  power  of  the 
soil  and  subsoil,  due  to  their  mineral  and  physical 
character  ;  and  thirdly,  the  amount  of  vegetable  matter 
(humus)  acquired  by  the  soil,  which  retards  the 
passage  of  water.  While  the  amount  and  time  of 
rainfall  cannot  be  controlled,  its  effect  upon  our  soils 
in  this  direction  can  be  largely  governed  if  proper 
attention  is  given  to  correcting  the  other  conditions, 
and  these  may  be  largely  modified,  if  not  entirely 
controlled.  In  the  matter  of  the  absorptive  and  reten- 
tive power  of  soils,  it  has  been  shown  that  if  they  are 
well  supplied  with  vegetable  matter  and  carefully 
cultivated,  they  retain  and  hold  the  plant -food  con- 
stituents in  a  much  greater  degree  than  if  devoid  of 
humus  and  improperly  managed,  and  also  that  the 
drainage  water  from  soils  upon  which  crops  are  grow- 
ing seldom  contains  more  than  the  merest  trace  of 
nitrates.  The  loss  of  nitrogen  through  the  opera- 
tion of  the  forces  of  nature  may,  therefore,  be 
reduced  by  the  careful  management  of  the  soil. 


10  FERTILIZERS 

Importance   of  Careful    Culture 

The  presence  of  suitable  amounts  of  vegetable 
matter,  and  good  cultivation,  are  conditions  that  are 
within  the  power  of  all  farmers  to  provide,  though  it 
is  sometimes  impracticable  to  keep  the  land  contin- 
uously covered  with  a  crop ;  and  sometimes  it  is 
thought  that  the  loss  incurred  through  leaching  be- 
cause of  the  absence  of  a  growing  crop  is  more  than 
balanced  by  the  gain  in  other  directions.  For  example, 
though  losses  of  nitrates  may  occur,  the  gain  in 
availability  of  the  mineral  constituents,  phosphoric 
acid  and  potash,  with  the  accompanying  improvement 
in  texture,  due  to  the  exposure  of  the  soil  to  atmos- 
pheric influence,  more  than  balances  these  losses,  par- 
ticularly during  the  winter,  with  its  wide  changes  of 
temperature.  , 

Loss   of  Nitrogen   hy   Drainage 

It  has  been  shown  by  carefully  conducted  experi- 
ments, both  in  this  and  other  countries,  that  in  a 
season  of  average  rainfall  the  drainage  waters  carry 
away  from  one  acre,  from  uncropped  soils  only  fairly 
rich  in  plant  food,  as  much  as  37  pounds  of  nitrogen 
per  year,  while  when  continually  cropped  the  drainage 
waters  from  the  same  soils  contain  practically  no 
nitrogen.  This  difference  in  the  loss  of  nitrogen 
under  the  two  conditions  may  not  seem  a  great  matter 
at  the  first  glance,  but  a  careful  study  of  the  bearing 
of  this  loss  in  its  relation  to   crop  production   shows 


LOSS   OF  NITBOOEN  BY  DBAINAGH]  H 

that  it  is  really  a  serious  matter.  In  the  first  place, 
the  amount  of  possible  loss  annually  is  practically 
equivalent  in  nitrogen  to  the  amount  contained  in  two 
tons  of  timothy  hay,  or  in  one  ton  of  either  wheat, 
rye,  oats,  corn  or  buckwheat,  quantities  nearly  double 
the  average  yield  per  acre  of  these  crops  throughout 
our  whole  country;  and  in  the  second  place,  that  the 
nitrogen  which  is  carried  away  by  the  drainage  water 
is  in  the  very  best  form  for  feeding  the  plant,  or  it 
would  not  have  been  lost,  and  thus  its  loss  leaves  the 
soil  not  only  poorer  in  this  constituent  element,  but 
poorer  in  the  sense  that  the  remainder  of  it  in  the 
soil  is  in  a  less  useful  form. 


Escape  of  Nitrogen  into  the  Atmosphere 

Another  source  of  natural  loss  of  nitrogen  is  its 
escape  from  the  soil  as  gas  into  the  atmosphere.  This 
is  due  to  the  oxidation  of  the  vegetable  matter,  or  to 
"denitrification,"  which  takes  place  very  rapidly  when 
soils  rich  in  vegetable  matter  are  improperly  managed. 
The  possibilities  of  loss  in  this  direction  are  strongly 
shown  by  investigations  carried  out  at  the  Minnesota 
Experiment  Station  on  "the  loss  of  nitrogen  by  con- 
tinuous wheat  raising."*  The  results  of  these  studies 
show  that  the  total  natural  loss  of  nitrogen  annually 
was  far  greater  than  the  loss  due  to  the  cropping.  In 
other  words,  by  the  system  of  continuous  cropping, 
which    is    universally    observed    in    the    great    wheat 


♦University  of  Minnesota  Agricultural  Experiment  Station,  Bulletin  53. 


12  FERTILIZERS 

fields  in  the  Northwest,  there  were  but  24.5  pounds 
of  nitrogen  removed  in  the  crop  harvested,  while  the 
total  loss  per  acre  was  171  pounds,  or  an  excess  of 
146  pounds,  a  large  part  of  which  loss  was  certainly 
due  to  the  rapid  using  up  of  the  vegetable  matter  by 
this  improvident  method  of  practice.  Whereas,  on 
the  other  hand,  when  wheat  was  grown  in  a  rotation 
with  clover,  the  gain  in  soil  nitrogen  far  exceeded 
that  lost  or  carried  away  by  the  crop.  The  continuous 
wheat-  and  corn -growing  in  the  West,  and  of  cotton 
and  tobacco  in  the  southern  states,  are  responsible 
for  untold  losses  in  this  expensive  element  of  fertility, 
while  in  nearly  every  state  of  the  Union,  soils  both 
rich  and  poor  are  suffering  more  or  less  from  the 
effect  of  natural  losses  in  this  direction 

THE    NATURAL    LOSS    OF    THE    MINERAL    ELEMENTS 

In  the  case  of  the  minerals,  phosphoric  acid  and 
potash,  which  exist  in  fixed  compounds  in  the  soil,  the 
actual  losses  are  undoubtedly  very  much  less  than  is  the 
case  with  nitrogen,  since  only  traces  of  these  constitu- 
ents are  ever  found  in  -solution  in  the  drainage  waters 
under  ordinary  circumstances;  yet,  because  of  the  large 
quantity  of  water  that  passes  through  many  of  our 
soils,  the  total  amount  of  these  rendered  soluble  and 
carried  away  by  this  means  is  very  great.  Our  great 
rivers  carry  in  solution  into  the  ocean  tons  upon  tons 
annually  of  these  elements  of  fertility,  and  it  is  an 
absolute  loss,  as  there  is  no  natural  means  by  which 
these  may  be  returned  to  the  soil,  as  is  the  case  with 


MECHANICAL   LOSSES   OF   FERTILITY  13 

nitrogen;  and  it  is  true,  as  in  the  case  of  the  former, 
that  the  soil  is  not  only  absolutely  poorer  by  virtue 
of  the  loss  of  its  elements  of  fertility,  but  poorer 
in  the  sense  that  the  immediate  utility  of  those  re- 
maining is  reduced.  These  silent  and  unseen  forces 
constantly  at  work  are  reducing  the  content  of  these 
constituents  in  our  soils  to  an  alarming  degree,  and 
it  is  because  they  are  unrecognized  forces  that  the 
disastrous  results  of  their  activity  are  not  fully  appre- 
ciated, and,  consequently,  the  best  means  for  restor- 
ing them  are  not  used. 

Losses  Due  to  Mechanical  Means 

A  serious  loss  of  all  of  the  fertility  elements  is 
also  due  to  mechanical  means.  Aside  from  the  amounts 
that  the  rivers  of  water  are  carrying  in  solution  into 
the  seas,  immense  amounts  are  carried  in  them  in 
suspension.  The  results  of  this  kind  of  loss  are  pain- 
fully evident ;  in  many  of  the  southern  states,  and  in 
sections  where  the  forests  have  been  removed  and  the 
land  abandoned,  the  soils  have  been  washed  and 
gullied  until  not  only  the  very  best  portions,  but  in 
some  cases  the  largest  portions,  have  been  carried 
away. 

It  is  not,  however,  in  the  abandoned  parts  of 
the  country  alone  that  these  mechanical  losses  of  con- 
stituents are  of  importance — they  are  more  or  less 
apparent  on  every  farm,  and  are  measured  by  the 
methods  of  management.  Soils  that  are  allowed  to 
lie  bare  and  fully  exposed  to  the  storms  of  wind  and 


14  FERTILIZERS 

rain  througnout  the  larger  portion  of  the  year  suffer 
the  greatest  loss,  while  from  those  which,  on  the 
other  hand,  have  crops  growing  during  a  large  part 
of  the  year,  and  which  hold  the  soil  particles  together 
and  prevent  their  easy  movement,  the  losses  are  re- 
duced in  both  the  directions  mentioned.  The  benefi- 
cial results  derived  from  the  use  of  good  methods 
are  cumulative ;  the  benefit  is  not  only  immediate, 
but  continuous. 

ARTIFICIAL    LOSSES    OF    FERTILITY 

In  addition  to  these  natural  losses  of  fertility,  there 
are  the  artificial  losses  of  the  constituents,  or  those 
due  to  the  removal  of  crops.  These,  of  course,  neces- 
sarily accompany  all  farming  operations,  and,  provided 
that  in  the  removal  and  sale  of  the  constituents  in 
the  form  of  crops,  the  farmer  has  received  a  fair 
price  for  them,  they  are  entirely  legitimate. 

The  sale  of  farm  products  is  really  in  the  last 
analysis  a  sale  of  actual  constituents,  together  with 
a  certain  portion  of  the  "  condition "  of  our  land, 
which  is  not  readily  measurable.  That  is,  it  is  the 
constituents  in  the  soil,  together  with  the  conditions 
surrounding  it,  that  the  farmer  buys  when  he  buys 
land.  If  an  acre  of  land,  containing  within  the  reach 
of  the  roots  of  the  plant,  say  3,000  pounds  of  nitro- 
gen, 5,000  pounds  of  phosphoric  acid  and  6,000  pounds 
of  potash,  sells  for  $100,  the  seller  receives  the  $100, 
not  for  so  much  dirt,  but  really  for  the  constituents 
contained  in  it.     The  purchaser  believes  that,  with  the 


ABTIFICIAL  LOSSES   OF  FERTILITY  15 

conditions  surrounding  them,  he  can  convert  them 
into  products  which  he  can  sell  and  from  which  rea- 
lize a  profit.  If  in  selling  these  amounts  of  the  con- 
stituents in  the  form  of  land,  a  lower  price  per  acre 
is  received,  it  is  because  the  natural  conditions  which 
surround  them,  and  which  influence  their  utility,  are 
less  favorable,  and  a  greater  proportionate  effort  and 
expense  are  necessary  to  secure  them  in  the  form  of 
salable  products.  The  difference  in  the  price  of  land 
is  not  always  due  to  the  content  of  the  constituents, 
but  often  to  the  conditions  surrounding  them.  In 
many  cases,  the  soil  may  serve  simply  as  a  medium  in 
which  plants  can  grow,  and  the  content  of  the  fertility 
elements  is  of  minor  importance.  Such  would  be  the 
case  in  the  growing  of  market -garden  crops  near 
large  cities,  the  location  near  the  consumer  being  of 
greater  importance,  in  the  case  of  perishable  crops  of 
this  sort,  than  the  chemical  character  of  the  soil.  In 
the  large  majority  of  cases,  however,  the  natural  fer- 
tility fairly  measures  the  market  price.  At  the  price 
per  acre,  and  for  the  quantity  of  constituents  here 
assumed,  the  buyer  would  pay  at  the  rate  of  1%  cents 
per  pound  for  the  nitrogen,  and  %  cent  per  pound 
each  for  the  phosphoric  acid  and  potash,  and  it  now 
constitutes  his  capital  stock. 

A  Comparison  of  the  Prices  Received  for  the  Fertility 
Elements  in   Different    Crops 

A  comparison  of   the  prices  paid  for  the  constitu- 
ents in   land,  with   the   prices   received  for   the  same 


16  FERTILIZERS 

constituents  when  contained  in  the  different  crops 
(disregarding  for  the  moment  the  value  of  the  "con- 
dition" of  soil),  will  make  clearer  this  matter  of 
rational  sale  of  constituents,  which  represents  a  re- 
duction of  our  capital  stock  of  fertility.  For  exam- 
ple, if  wheat  is  raised,  which  contains  1.89  per  cent 
of  nitrogen,  .93  per  cent  of  phosphoric  acid  and  .64 
per  cent  of  potash — or  in  round  numbers,  38  pounds 
of  nitrogen,  19  of  phosphoric  acid  and  13  of  potash 
per  ton — and  is  sold  for  60  cents  per  bushel,  or  $20 
per  ton,  the  nitrogen  sells  in  this  form  for  41  cents 
per  pound,  and  the  phosphoric  acid  and  potash  for 
14  cents  each  per  pound.  That  is,  the  60  cents  per 
bushel,  or  the  41  cents  per  pound,  received  for  the 
nitrogen,  and  14  cents  for  the  potash  and  phosphoric 
acid,  represent  what  has  been  received  per  pound  for 
the  capital  stock  of  these  elements,  which  at  $100 
per  acre  were  purchased  at  the  prices  previously  men- 
tioned. The  labor  in  raising  the  crop,  the  expense  of 
harvesting  and  putting  it  upon  the  market,  and  the 
profit,  must  come  out  of  the  difference  between  what 
is  paid  and  what  is  received.  Naturally,  as  the  ratio 
between  the  constituents  contained  in  the  products 
sold  and  the  price  received  is  increased,  the  rate  of 
income  per  unit  of  exhaustion  is  increased,  though 
in  many  cases  the  increased  cost  of  the  labor  neces- 
sary is  in  proportion  to  the  increased  price  received. 
This  may  be  illustrated  by  a  comparison  on  the  fer- 
tility basis  of  the  sale  of  wheat  and  milk.  If  milk, 
which  contains  on  the  average  12  pounds  of  nitrogen, 
4%^   pounds   of    phosphoric   acid   and    3^    pounds   of 


FERTILITY    CONTENT    OF   FABM    GBOPS  17 

potash  per  ton,  is  sold  for  $1.50  per  hundred  pounds, 
the  nitrogen  is  sold  for  $2  per  pound,  and  the  phos- 
phoric acid  and  potash  for,  approximately,  70  cents 
per  pound.  In  the  sale  of  milk  at  this  price,  the  rate 
of  income  per  unit  of  exhaustion  is  increased  nearly 
five  times  over  that  of  the  wheat,  though,  because  it 
is  in  one  sense  a  manufactured  product,  the  cost  of 
labor  per  unit  of  plant -food  contained  is  largely  in- 
creased. Again,  if  cream  is  sold,  the  prices  received 
for  the  constituents  are  still  further  increased,  while 
if  the  milk  is  made  into  butter,  and  that  alone  is 
sold,  the  prices  received  measure  the  expenses  and 
profit,  and  the  capital  stock  of  fertility  is  not  mate- 
rially reduced,  though  it  is  in  another  form  and  in 
another   place. 

Fertility  Content  of  Cereals  and  Vegetables 

The  losses  of  the  constituents  in  the  sale  of  ce- 
reals and  grasses,  corn,  oats,  wheat  and  hay,  are,  too, 
relatively  greater  than  in  the  sale  of  vegetables  and 
fruits,  as  lettuce,  celery,  potatoes,  tomatoes,  sugar 
beets,  apples,  berries  and  kindred  crops,  though  in 
the  case  of  the  latter,  a  higher  degree  of  fertility  is 
necessary  in  order  to  produce  maximum  crops,  and 
the  cost  of  production  is  again  proportionately  greater. 
Thes^  facts  strongly  emphasize  the  necessity  of  a  care- 
ful study  of  the  relation  of  farm  practice  to  the  arti- 
ficial losses  of  fertility. 

The  artificial  loss  of  fertility  that  may  be  incurred 
by  the  sale  of  crops  is  largely  measured  by  the  knowl- 


18  FERTILIZERS 

edge  of  the  producer  concerning  the  relation  between 
the  price  received  for  the  crop  and  the  fertility  con- 
tained in  it,  and  thus  removed  when  sold,  and  by  his 
intelligence  in  adjusting  his  methods  so  as  to  reduce 
to  a  minimum  the  actual  loss. 

Irrational  Farm  Practice 

There  are  methods  of  practice  which  are  entirely 
irrational,  and  contribute  to  the  real  losses  of  fertility. 
Farming  is  unprofitable,  not  altogether  because  the 
land  is  exhausted,  but  because  only  those  crops  are 
grown  which  possess  a  high  fertility  value,  and  which 
have  a  low  market  price,  and  thus  the  prices  received 
for  the  constituents  in  the  crop  are  actually  less  than 
they  cost  in  land  and  in  labor ;  and  these  methods  of 
practice  are  not  confined  to  farmers  whose  lands  of 
inexhaustible  fertility  have  been  given  them  by  a 
generous  government,  but  are  followed  by  farmers 
who  annually  purchase  commercial  fertilizers  to  supply 
the  losses  of  fertility  thus  sustained. 

Where  the  conditions  are  such  as  to  make  it  im- 
practicable to  grow  and  sell  crops,  as  such,  of  a  low 
fertility  value,  the  producer  should  endeavor  to  sell 
the  manufactured  rather  than  raw  materials, —  that 
is,  to  so  use  his  crude  products  as  to  lower  the  quan- 
tity of  the  constituents  contained  in  those  sold,  "C^hich 
explains,  in  part,  the  greater  success  in  the  long  run 
of  a  miKcd  husbandry,  rather  than  single -crop 
farming. 

The  artificial  losses  of  our  national  capital  stock  of 


IRRATIONAL    FARM   PRACTICE  19 

fertility  are,  however,  not  absolute,  if  the  products 
are  consumed  in  our  own  country,  as  more  or  less  of 
the  constituents  contained  in  the  crude  'products  sold 
find  their  way  back  to  the  farm,  either  in  the  by- 
products of  the  mills,  in  sewage,  in  the  manure  from 
cities,  or  in  various  vegetable  or  animal  wastes  ;  but 
when  they  are  exported  the  loss  is  absolute,  and  the 
amounts  so  disposed  of  are  in  some  degree  a  measure 
of  the  rate  of  loss  of  the  capital  stock  of  fertility  in 
our  lands,  though  to  these  must  be  added  the  losses 
due  to  the  improper  use  of  manure  and  other  waste 
materials. 

Losses  in  Manures 

It  is  natural  to  infer  that  proper  losses  of  fertility 
are  confined  to  the  removal  of  the  constituents  in  the 
sale  of  farm  products,  and  that  those  contained  in  the 
materials  not  sold  and  in  the  feeds  used  upon  the  farm, 
are  again  returned  to  the  land.  Theoretically  this  is 
correct,  but  the  losses  that  do  occur,  particularly  in 
the  handling  of  manures,  should  not  be  overlooked. 
While  it  is  impossible  to  even  roughly  estimate  the 
waste  or  loss  of  fertility  due  to  the  improper  making 
or  handling  of  manures,  some  idea  may  be  obtained 
when  the  enormous  amounts  produced  and  the  sources 
of  possible  loss  are  considered. 

If'  this  enormous  mass  of  waste  material  were 
properly  used,  it  would  go  a  great  way  toward  increas- 
ing the  present  and  immediate  fertility  of  our  soils,  or 
in  retarding  the  time  of  exhaustion,  and  it  is  quite 
pertinent   to    inquire   if    it   is   properly  used.      It   has 


20  FERTILIZERS 

been  demonstrated  by  experiments*  that  50  per  cent 
of  the  total  constituents  in  farm  manures  is  liable  to 
be  lost  by  ill -regulated  fermentation  and  by  leaching ; 
and  further,  careful  observations  and  experiments 
show  that  the  conditions  in  the  majority  of  barnyards 
are  such  as  to  encourage  the  maximum  loss  by  these 
means.  It  is  morally  certain  that  a  large  percentage 
of  the  constituents  contained  in  them  are  lost ;  they 
never  reach  the  right  place  od  the  farm. 

It  is  estimated  that  if  but  one -tenth  of  the  present 
waste  could  be  avoided, —  and  a  very  large  part  of  it  is 
practically  avoidable,  and  at  a  very  slight  expense, — 
the  total  amount  of  constituents  that  may  thus  be 
saved  for  further  use  would  be  more  than  equivalent 
to  the  amounts  now  purchased  in  the  form  of  com- 
mercial fertilizers.  This  estimate  is  certainly  conser- 
vative, and  clearly  demonstrates  the  serious  drain 
upon  our  resources  of  fertility  elements,  due  to  the 
lack  of  care  in  the  handling  of  farm  manures. 

The  conditions,  as  here  pointed  out,  not  only  sug- 
gest the  need  of  imported  plant -food,  but  that  there 
are  opportunities  for  reducing  this  need  by  careful 
saving  and  use  of  the  constituents  that  are  subject  to 
waste. 


♦Bulletin  56,  Cornell  Univ.  Agr.  Ex.  Sta.,  Ithaca,  N.  Y. 


CHAPTER  II 

THE  FUNCTION  OF  MANURES  AND   FERTILIZERS,  AND 
THE   NEED    OF  ARTIFICIAL   FERTILIZERS 

While  in  a  broad  sense,  a  manure  or  fertilizer  may 
be  regarded  as  anything  that  will  increase  the  yield  of 
a  crop  if  added  to  the  land,  the  chief  function  of 
manures  is  to  furnish  nitrogen,  phosphoric  acid  and 
potash. 

THE    ESSENTIAL    ELEMENTS    OF    FERTILIZERS 

These  are  called  the  "essential  manurial  elements," 
or  "constituents,"  to  distinguish  them  from  the  others 
that  are  needed  by  plants,  because  these  three  are  con- 
tained in  the  crops  removed  in  greater  amounts  than 
the  others,  and  because  they  exist  in  the  soil  in  much 
smaller  amounts  than  the  others.  For  example,  culti- 
vable soils  seldom  contain  too  little  iron  or  sulfur,  or 
magnesium.  These  elements  usually  exist  in  quantities 
more  than  sufficient  to  supply  all  the  needs  of  the 
plant  for  them,  and,  because  they  are  required  in  such 
exceedingly  small  amounts,  the  soils  are  seldom  ex- 
hausted of  them.  In  addition  to  this  property  of 
supplying  essential  manurial  constituents,  many  sub- 
stances useful  as  manures  possess,  however,  a  secondary 
function  :    they  serve  to    indirectly  increase   the  crop, 

(21) 


22  FERTILIZERS 

but  do  not  add  directly  to  the   potential  fertility  of 
soils. 

NATURAL    MANURES    AND    ARTIFICIAL    FERTILIZERS 

Farmyard  manure,  and  many  other  natural  pro- 
ducts, possess  this  second  function  in  a  marked  de- 
gree, and  the  indirect  manurial  value  of  these  is  due 
largely  to  the  good  effect  that  the  substances  asso- 
ciated with  the  nitrogen,  phosphoric  acid  and  potash 
in  them  exert  in  increasing  the  crop.  This  good 
effect  is  observed  in  two  directions.  First,  the  vege- 
table matter  contained  in  the  natural  manure  improves 
the  physical  character  of  soils — those  that  are  clayey 
and  compact,  by  making  them  more  open  and  porous, 
separating  the  particles,  so  that  the  water  and  air  can 
penetrate  more  freely,  and  thus  act  directly  upon  the 
dormant  or  insoluble  constituents  that  are  contained 
in  it ;  and  those  that  are  light  and  sandy,  by  filling 
up  the  open  spaces,  thus  making  them  more  compact. 
In  the  second  place,  the  addition  of  vegetable  matter 
to  soils,  even  though  it  contains  no  essential  consti- 
tuents, improves  it  by  enabling  it  to  more  readily  and 
completely  absorb  and  retain  not  only  the  water,  but 
also  the  soluble  essential  constituents  that  may  be 
added.  The  chief  distinction  between  what  are 
known  as  manures  and  what  are  known  as  ferti- 
lizers, is  the  difference  in  respect  to  this  secondary 
function.  The  manure  possesses  the  two  functions, 
the  one  to  supply  the  essential  constituents,  and  the 
other  to  assist  plant  growth  by  aiding  in  the  improve- 
ment of  those  ah'eady  contained  in  the  soil,  and  this 


THE    FUNCTIONS    OF    MANURES  23 

latter  function  it  exerts  in  a  marked  degree;  while  the 
fertilizer,  as  a  rule,  possesses  but  one,  namely,  that 
of  furnishing  plant -food.  The  indirect  effect  of  the 
materials  associated  with  the  constituents  in  artificial 
fertilizers  is  seldom  very  useful,  and  sometimes  may 
be  harmful. 

DIRECT    AND    INDIRECT    EFFECT    OF    MANURES 

It  is  obvious,  therefore,  that  any  substance  which 
contains  nitrogen,  phosphoric  acid  or  potash  may 
serve  as  a  direct  manure,  and  any  substance  which 
contains  no  plant -food,  but  which  possesses  the  power 
of  improving  the  physical  character  of  soils,  may  also 
serve  as  a  manure,  though  the  one  effect  is  quite  dis- 
tinct from  the  other.  The  first  adds  to  the  soil  the 
essential  constituents;  the  other  helps  to  make  the  con- 
stituents already  in  the  soil  serve  as  food  to  the  plant. 

The  use  of  the  one  will  tend  to  increase  both  the 
potential  and  practical  fertility  in  the  soil,  while  by 
the  use  of  the  other,  the  active  fertility  is  increased 
as  the  potential  fertility  is  decreased.  That  is,  when 
actual  plant -food  is  added  in  the  form  of  nitrogen, 
phosphoric  acid  or  potash,  and  crops  are  removed,  the 
exhaustion  of  the  soil  is  in  proportion  to  the  amounts 
of  these  removed  over  and  above  the  amounts  which 
have  been  added.  Whereas,  in  the  other  case,  when 
no  plant -food  is  added,  the  exhaustion  is  measured  by 
the  amount  of  the  constituents  removed.  It  is  clear, 
therefore,  that  the  addition  of  only  indirect  manures 
has  a  tendency  to   rapidly  reduce  the  fertility  of   soils 


24  FERTILIZERS 

of  low  natural  strength,  or  those  that  do  not  possess 
large  stores  of  food  constituents,  whereas,  on  soils 
that  are  rich  in  the  fertility  elements,  the  indirect 
manuring  may  result  in  an  increased  yield  for  a  long 
period,  though  ultimately  the  soil  will  become  ex- 
hausted— if  not  completely,  to  such  a  degree  as  to 
render  further  cropping  by  this  method  unprofitable. 

UNAVAILABLE  AND  AVAILABLE  PLANT -FOOD 

While,  as  already  stated,  any  material  containing 
either  one  or  all  of  the  three  essential  constituents, 
nitrogen,  phosphoric  acid  or  potash,  may  serve  as  a 
direct  manure  in  the  sense  that  it  increases  the  poten- 
tial fertility  of  any  soil,  the  value  of  the  addition  of 
such  materials  will  depend  not  so  much  on  the 
amount,  as  upon  the  power  that  the  plant  may 
possess  of  acquiring  it — and  it  is  here  that  the  dif- 
ference between  manures  from  natural  sources  and 
those  from  artificial  sources  is  again  quite  manifest. 
That  is,  the  fertility  constituents  in  natural  manures 
are  in  large  part  combined  with  others  in  the  form  of 
vegetable  matter,  and  with  the  exception  of  potash, 
they  are,  when  in  this  form,  largely  insoluble,  and, 
therefore,  cannot  be  used  by  the  plants  until  after 
decay  begins,  "Whereas,  in  artificial  manures,  the 
constituents  may  be  not  only  soluble,  but  may  be  in 
a  form  in  which  the  plants  can  take  them  up  im- 
mediately. In  the  first  case,  the  plant -food  is  said 
to  be  unavailable,  and  in  the  second,  it  is  said  to  be 
available. 


AVAILABLE    PLANT-FOOD  25 

Nitrogen,  one  of  the  chief  constituents  of  manures, 
for  example,  exists  in  three  distinct  forms:  (1)  the 
organic  form,  in  animal  or  vegetable  matter,  which 
must  first  decay  before  it  can  serve  as  plant -food,  (2) 
As  the  decay  goes  on  ammonia  is  formed,  and  then 
(3)  from  the  ammonia  the  nitrate  is  formed,  which  is 
the  form  in  which  plants  take  up  the  largest  proportion 
of  their  nitrogen.  Inasmuch  as  products  exist  which 
contain  nitrogen  in  these  three  distinct  forms,  it  is 
possible  by  their  use  to  largely  control  the  feeding  of 
the  plant  in  respect  to  this  element,  while  in  the  case 
of  natural  manures,  the  feeding  of  the  plant  with 
nitrogen  depends  upon  conditions  which  cause  its 
change  from  the  organic  into  the  other  forms. 
As  these  conditions  are  variable,  the  problem  of 
the'  economical  feeding  of  plants  with  nitrogen,  other 
things  being  equal,  becomes  a  more  difficult  matter 
with  the  natural  than  with  the  artificial  manures. 

Phosphoric  acid  also  exists  in  different  forms,  the 
form  measuring  to  a  large  degree  its  availability  :  the 
organic,  in  which  the  availability  depends  upon  the 
rapidity  of  decay ;  and  the  soluble  and  immediately 
available  form, — that  is,  the  form  that  distributes 
everywhere,  and  which  the  plant  can  absorb  immedi- 
ately it  comes  in  contact  with  the  roots.  Commercial 
products  exist  which  contain  the  phosphoric  acid  in 
these  distinct  forms.  The  user  is  therefore  enabled 
to  supply  this  constituent  in  such  form  as  may  best 
suit  his  crop  and  soil  conditions. 

In  the  case  of  potash,  distinct  forms,  as  muriate, 
sulfate   and   carbonate,  also   exist,   though  in  the  case 


26  FERTILIZERS 

of  potash,  the  form  iu  which  it  is  combined  exerts 
less  influence  upon  the  availability  of  the  element  to 
the  plant  than  is  the  case  with  nitrogen  and  phos- 
phoric acid.  All  of  these  forms  are  soluble,  and  can 
be  readily  absorbed. 

DANGER  OF  LOSS  FROM  THE  USE  OF  SOLUBLE 
PLANT -FOOD 

The  fact  that  the  artificial  fertilizer -products  con- 
tain the  constituents  in  such  forms  and  combinations 
as  to  enable  them  to  feed  the  plant  immediately,  also 
presents  some  disadvantages  from  the  standpoint  of 
economical  use.  This  is  particularly  true  in  the  case 
of  nitrogen,  for  nitrogen,  when  applied  in  the  form 
of  nitrate,  in  which  form  it  is  taken  up  by  the  plant, 
does  not  combine  to  make  insoluble  compounds,  but 
remains  freely  soluble.  A  great  waste,  therefore,  may 
ensue  from  leaching  into  the  lower  layers  of  the  soil 
and  beyond  the  roots  of  plants,  or  into  the  drains, 
and  the  plant -food  be  carried  away,  unless  care  is 
exercised  both  as  to  the  amount  and  the  method  of 
application.  With  soluble  phosphates,  the  danger  of 
loss  is  much  less  than  with  nitrogen.  If  these  are  ap- 
plied in  too  large  quantities  to  meet  the  needs  of  the 
plants,  or  under  improper  conditions,  their  tendency 
is  not  to  remain  soluble,  but  to  revert  to  their 
original  and  insoluble  form.  The  main  fact,  however, 
is  that  in  artificial  fertilizers  we  may  have  the  con- 
stituents in  distinct  and  separate  forms,  which  permits 
the  feeding  of  the   plant,  rather  than  the  feeding   of 


CHEMICAL   FERTILIZERS   ARE   EFFICIENT        27 

the  soil ;  and  this  is  usually,  and  must  necessarily 
be,  the  case  when  natural  manure  products  serve  as 
the  entire  source  of  the  added  fertility. 

THE    USEFULNESS    OF    A    FERTILIZER    CONSTITUENT    DOES 
NOT    DEPEND    UPON    ITS    ORIGINAL    SOURCE 

It  should  be  remembered,  too,  that  artificial  ma- 
nures or  fertilizers  supply  plant -food  just  as  well  as 
other  and  more  common  products.  The  fact  that 
the  food  exists  in  substances  other  than  those  which 
are  familiar  to  the  farmer,  is  no  evidence  that  it  may 
not  be  quite  as  good,  or  even  better,  than  when  con- 
tained in  his  home-made  products.  It  is  not  the  out- 
ward appearance  of  a  substance,  but  the  kind  and 
form  of  the  elements  contained  in  it,  that  measures 
its  value  as  a  fertilizer. 

For  example,  the  nitrogen  that  may  be  applied  in 
the  form  of  a  commercial  fertilizer  exerts  no  different 
function  in  the  plant  than  that  which  may  be  acquired 
from  the  original  soil,  or  from  materials  that  have 
recently  been  obtained  from  that  soil,  and  again 
returned  as  yard  manure.  The  same  is  true  of  phos- 
phoric acid  and  potash.  In  their  concentrated,  artificial 
forms,  they  serve  to  feed  the  plants  in  exactly  the 
same  way,  and  exert  the  same  function  in  them,  as 
those  contained  in  the  soils  themselves,  or  that  may  be 
contained  in  wood  ashes,  or  materials  more  familiar, 
or  of  more  common  occurrence.  The  form  in  which 
they  exist  when  applied  does  not  necessarily  imply 
that  they  are  stimulants  rather  than  food,  though  fre- 


28  FERTILIZERS 

quently,  because  of  their  form,  the  plants  are  able  to 
absorb  them  more  readily,  and  thus  by  their  rapidly 
increased  growth,  encourage  a  belief  that  an  undue 
stimulating  effect  accompanies  their  use.  The  famous 
experiments  of  Lawes  &  Gilbert,  at  Rothamsted, 
England,  teach  this  one  thing  very  emphatically;  viz., 
the  efficiency  of  chemical  fertilizers  as  compared  with 
yard  manures.* 

USE    OP    FERTILIZERS 

While  manures  in  the  ordinary  sense,  and  even 
materials  which  are  now  included  under  the  head  of 
artificial  manures,  such  as  ground  bone  and  wood 
ashes,  have  been  used  for  a  very  long  time,  the  use 
of  artificial  products  in  a  true  sense  is  of  compara- 
tively recent  origin.  The  first  use  of  genuine  artificial 
fertilizers  dates  from  the  publication  of  Baron  von 
Liebig's  book,  "Organic  Chemistry  in  Its  Application 
to  Agriculture  and  Physiology,"  in  1840 ;  yet  for  a 
long  time  after  this  date  the  increase  in  their  use  was 
very  gradual.  The  very  excellent,  and  at  that  time 
surprising,  results  which .  were  obtained  from  the 
application  of  Peruvian  guano,  one  of  the  first 
products  to  receive  attention,  manifestly  increased  the 
interest  in  the  subject,  also.  These  good  results  were 
observed  more  particularly  on  the  continent  of 
Europe,  where  the  lands  had  been  under  cultivation 
for  a  long  time.  The  use  in  America,  previous  to 
1860,    was    quite    insignificant.      Since    the    work    of 


*  Rothamsted  Memoirs,  Volumes  i.-vi. 


TEE    USE    OF   FERTILIZERS  29 

Liebig,  a  very  great  amount  of  study  has  been  given 
to  the  subject,  both  in  reference  to  the  essential  char- 
acter of  the  various  materials,  and  their  influence 
upon  the  production  of  plants.  Perhaps  no  other 
single  subject  relating  to  agricultural  science  has  been 
studied  more  fully  than  the  question  of  the  use  of 
artificial  manures ;  and  these  studies  have  resulted, 
not  only  in  the  discovery  of  new  materials,  but  in 
their  better  preparation  for  use  as  plant -food,  which 
greatly  increased  their  effective  use.  There  is  no 
question  connected  with  agriculture  which  is  of  greater 
direct  and  practical  importance,  particularly  in  those 
oountries  which  have  been  depleted  of  their  active 
fertility  by  the  means  mentioned,  or  in  which  the 
conditions  are  as  previously  outlined,  than  definite 
knowledge  of  the  true  principles  which  govern  in  the 
profitable  use  of  commercial  fertilizers.  Yet,  not- 
withstanding all  the  good  results  thus  obtained,  and 
their  great  practical  importance  to  agriculture,  much 
still  remains  to  be  done,  particularly  in  the  establish- 
ment of  fundamental  principles. 

While  it  is  desirable  that  in  a  work  of  this  kind, 
scientific  discussions  should  be  avoided  as  far  as  pos- 
sible, and  the  subject  made  as  plain  as  is  practicable 
to  those  using  fertilizers,  it  is  necessary  to  their 
right  use  that  those  who  apply  them  to  their  land 
should  have  a  very  clear  conception  of  the  underlying 
principles,  so  far  as  they  are  known,  in  order  that 
they  may  intelligently  increase  their  production,  and 
thus  reap  a  profit.  Definite  knowledge  is  an  im- 
portant factor  in  determing  their  profitable  use. 


30  FEBTILIZEB8 

THE    NEED    OF    ARTIFICIAL    FERTILIZERS 

The  considerations  in  the  previous  chapter 
explained  in  part,  and  in  a  broad,  general  way,  the 
necessity  for  the  use  of  commercial  fertilizers.  The 
conditions  of  farming  in  this  country  have  greatly 
changed  in  the  past  thirty  years,  and  these  changes 
have,  perhaps,  a  still  more  important  bearing  in  show- 
ing the  need  of  imported  fertility  than  the  conditions 
already  discussed.  The  first  direction  in  which 
important  changes  have  taken  place  is  in  the  in- 
creased cost  of  farm  labor  and  in  the  relatively  low 
prices  now  received  for  the  staple  crops,  the  cereal 
grains,  cotton  and  tobacco. 

The    Cost    of    Production    per    Unit    of    Income 
is    Increased 

The  cost  of  labor  is  increased  because  proportion- 
ately higher  wages  are  now  paid,  and  because  the 
labor  now  obtainable  is  on  the  whole  less  efficient, 
being  performed  more  largely  by  those  untrained 
for  their  work,  rather  than  by  the  owner  and  his 
sons  ;  and  this  increased  cost  of  labor  makes  the  cost 
of  growing  the  staple  crops  much  greater  in  propor- 
tion to  their  market  value  than  was  formerly  the 
case,  though  there  are,  of  course,  exceptions. 

For  example,  harvest  wages  throughout  the  east- 
ern part  of  the  country,  at  any  rate,  were  in  the 
sixties  regulated  somewhat  by  the  price  of  wheat. 
When  wheat  was  $3   per  bushel  in  the  eastern  states, 


TEE    NEED    OF    FERTILIZERS  31 

the  daily  wage  was  $3.  Now  the  daily  wage  in  the 
east  ranges  from  $2  to  $2.50  per  day,  while  the  price 
of  wheat  does  not  often  exceeed  $1  per  bushel,  and 
the  price  received  is  frequently  much  lower  than 
this.  The  wages  for  other  kinds  of  farm  work  are 
proportionately  the  same  in  reference  to  present 
prices  of  products.  This  condition,  when  considered 
in  connection  with  the  important  fact  that  the  total 
cost  of  crop  per  acre  is  practically  the  same,  whether 
the  yield  is  high  or  low,  exerts  a  decided  influence 
in  determining  profits,  particularly  on  land  of 
medium  fertility.  The  cost  of  preparing  the  land  for 
the  seed,  the  cost  of  seed,  and  the  seeding  and 
harvesting,  are  the  same  for  a  crop  of  wheat,  whether 
the  yield  is  10  or  30  bushels  per  acre  ;  but  this  cost 
will  not  permit  a  profit  from  the  10 -bushel  yield, 
because  the  cost  per  bushel  is  too  largely  increased. 
The  same  considerations  hold  true  for  a  number  of 
other  crops.  Small  yields  of  these  relatively  low- 
priced  crops  cannot  be  profitably  produced  with  the 
present  high  price  of  labor ;  and  it  has  been  shown, 
furthermore,  that  land  which  is  not  in  a  high  state 
of  fertility  will  not  produce  large  yields. 

Many  soils,  especially  those  in  the  eastern  and 
southern  sections  of  our  country,  which  were  not 
originally  very  fertile,  and  which  have  been  cropped 
for  a  long  time,  show  abundant  evidence  of  the  need 
of  fertility  from  sources  outside  of  the  farm,  in  order 
that  maximum  crops  may  be  produced.  The  aim  should 
be,  therefore,  to  make  the  conditions  of  soil  better,  arid-^ 
if    possible,  so   perfect   as    to   guarantee    against  'any- 


32  FERTILIZERS 

lack  of  food  during  the  growing  period,  and  thus 
make  the  conditions  of  climate  and  season,  rather  than 
the  soil,  the  measure  of  the  crop.  That  is,  as  far  as 
practicable,  the  yield  that  it  is  possible  to  obtain  ia  a 
given  locality  should  be  the  aim  of  the  farmers  in  that 
locality.  In  order  to  make  the  conditions  of  soil  per- 
fect in  this  respect,  the  fertility  elements  must  be 
added,  though  indirect  manuring,  in  the  form  of  better 
cultivation  and  better  use  of  the  waste  products  of  the 
farm,  are  also  to  be  encouraged, 

A    Greater  Demand  for   Special    Crops 

In  the  second  place,  the  changed  conditions  of 
farming  are  shown  in  the  constantly  increasing  demand 
for  market -garden  products  and  fruits.  Not  many 
years  ago,  the  staple  crops  already  described  were  prac- 
tically the  only  ones  raised  and  sold  from  the  farm. 
The  growing  of  vegetables  and  fruits  was  limited.  They 
were  regarded  as  luxuries,  and  the  area  given  to  them 
was,  on  most  farms,  only  sufficient  to  meet  the  needs 
of  the  home.  These  were  not  regarded  as  crops  in  the 
same  light  as  the  others,  and  were  seldom  the  source 
of  direct  income.  At  the  present  time,  vegetables  and 
fruits  are  regarded  as  necessities  in  every  home,  and 
their  use  is  not  confined  to  the  season  in  which  they 
can  be  provided  in  the  immediate  vicinity  of  the  cities 
or  towns  where  they  are  used  ;  they  are  drawn  from 
points  far  distant,  and  the  demand  is  such  as  to  re- 
quire the  use  of  wide  areas  in  order  to  supply  the 
needs.     The  growing  of  market -garden  crops  and  fruits 


FARM    MANURES    ARE    INADEQUATE  33 

is   now   the    basis    of   specific    agricultural    industries 
which  have  assumed  large  proportions. 

Much  progress  has  been  made,  too,  in  the  develop- 
ment of  methods  of  practice  in  these  lines  of  farming, 
and  the  experience  gathered  has  shown  that  even  our 
most  fertile  soils  in  their  natural  conditions  contain 
too  little  active  food  to  insure  maximum  yields  of  crops 
of  the  best  quality ;  in  these  lines  of  farming,  too, 
earliness  and  edible  quality  of  products,  which  are 
influenced  by  the  food  supplj%  are  important  factors  in 
determining  the  profits  to  be  derived.  The  areas  now 
necessarily  d-evoted  to  these  crops  are  so  great  that 
soils  of  a  high  natural  fertility,  even  if  natural  fertility 
alone  could  be  depended  upon,  are  too  limited  to  meet 
the  demand  and  enable  a  profit,  especially  in  the  vicin- 
ity of  good  markets  ;  in  other  respects  a  good  location, 
because  permitting  of  cheap  distribution,  is  an  impor- 
tant factor. 

Farm   Manures   are   Inadequate 

Farm  manures  might  meet  the  needs  for  the  staple 
crops,  as  they  are  well  adapted  in  many  respects  for 
the  purpose,  but,  under  present  systems  of  manage- 
ment, the  amount  is  not  sufficient  to  meet  the  annual 
losses  from  the  sale  of  crops,  much  less  to  provide  an 
increase,  and  the  only  other  source  is  an  artificial 
supply,  or  commercial  fertilizers.  For  the  special 
crops  already  described,  the  natural  manures  of  both 
farm  and  city  are  not  only  not  sufficient,  but,  because 
of  their  character  and  composition,  are  not  well  adapted 
C 


34  FERTILIZERS 

to  economically  meet  the  entire  demands  of  the  plants. 
In  the  first  place,  they  are  bulky,  and  thus  expensive 
to  handle.  In  the  second  place,  the  fertility  elements 
contained  in  them  are  not  in  good  proportion ;  they 
are,  as  a  rule,  poor  in  the  mineral  elements  and  rich  in 
nitrogen,  and  their  use  in  sufficient  amounts  to  meet 
the  needs  of  the  plant  for  the  mineral  elements  results 
in  a  waste  of  the  nitrogen.  Third,  the  constituents 
contained  in  them  are  not  in  sufficiently  active  forms 
to  provide  for  a  rapid  and  continuous  growth  without 
an  excessive  application,  which  frequently  results  in  a 
serious  waste  not  only  of  the  nitrogen,  as  already  indi- 
cated, but,  in  the  case  of  many  crops,  an  abnormal 
growth  of  vine  or  stalks,  which  may  seriously  injure 
the  marketable  quality  of  the  crops.  For  many  crops, 
economical  production  requires  that  the  natural  ma- 
nures should  be  supplemented  by  artificial  supplies,  by 
means  of  which  the  form  and  amount  of  the  individual 
constituent  can  be  regulated  to  meet  the  needs  of  the 
various  plants. 

The  Growing  Importance  of  Fruit-growing 

In  fruit -culture,  an  industry  of  growing  importance, 
it  has  been  found  that  soils  in  their  natural  condition, 
while  they  may  be  well  adapted  in  other  respects — that 
is,  possess  a  suitable  physical  character  for  the  growth 
of  this  class  of  crops — contain  insufficient  amounts  of 
the  mineral  constituents  which  are  required  in  order 
that  continuous  and  large  crops  of  perfect  fruit  may 
be  secured.     To  supply  this  deficiency  from  vard  ma- 


THE  BIGHT   USE   OF  FJEBTILIZEBS  35 

nure  would  cause  in  many  cases  an  over -supply  of  vege- 
table matter  containing  nitrogen,  which  for  these  crops 
is  frequently  followed  by  disastrous  results,  not  only 
causing  an  abnormal  growth  of  leaf  and  wood,  but 
inducing  it  at  such  periods  of  the  year  as  to  materially 
interfere  with  the  proper  ripening  of  both  the  wood 
and  the  fruit.  By  the  use  of  artificial  fertilizers,  these 
difficulties  may  be  largely  overcome. 

WILL    IT    PAY    TO    USE    FERTILIZERS? 

It  must  be  confessed  that  to  give  a  definite  and 
positive  answer  to  this  question,  with  our  present  state 
of  knowledge,  is  a  difficult  matter,  if  not  well-nigh 
impossible,  because  of  the  very  large  number  of  vary- 
ing conditions  that  are  involved. 

Usually  such  a  question  cannot  be  answered  in  a 
rational  way  without  first  securing  definite  information 
concerning  the  conditions  under  which  they  are  to  be 
applied,  as,  for  instance,  the  character  of  soil,  whether 
a  sand,  clay  or  loam;  situation  in  reference  to  mois- 
ture, whether  too  dry  or  too  wet;  the  kind  of  subsoil, 
whether  a  loose,  open  sand  or  gravel,  a  medium  clay, 
or  a  tight,  impervious  hard-pan;  the  character  of  the 
previous  treatment  and  cropping,  whether  the  land  has 
been  manured  or  fertilized,  whether  good  cultivation 
has  been  practiced,  whether  leguminous  crops  have 
been  grown  to  any  extent,  whether  the  produce  raised 
has  been  sold,  or  fed  on  the  land;  whether  the  object 
of  the  growth  has  been  for  immature  produce  and  for 
early    market,    and     artificial    growth    demanded,    or 


36  FERTILIZERS 

whether  for  maturity,  when  the  natural  tendency  has 
simply  been  assisted  and  the  development  normal  in 
all  directions. 

If  these  questions  are  answered  truthfully  and  in 
detail,  a  scheme  of  fertilization  may  be  adopted  that 
wUl  enable  the  farmer  to  secure  the  greatest  returns 
for  the  plant -food  applied. 

That  the  returns  from  the  use  of  fertilizers  are 
frequently  unprofitable,  is  not  always  the  fault  of  the 
fertilizer,  and  this  point  may  be  illustrated  by 
the  following  typical  case:  One  farmer  applies 
plant-food,  his  crop  is  doubled  or  trebled,  and  a  rea- 
sonable profit  is  secured.  Another  farmer  applies  the 
same  amount  and  kind  of  fertilizer  under  similar 
natural  conditions  of  soil,  and  he  receives  no  benefit. 
The  same  climatic  conditions  surrounded  the  crops  of 
both,  the  sun  that  warmed  the  soil  and  furnished  the 
energy  necessary  for  the  production  of  the  largely 
increased  crop,  is  the  same  sun  that  shone  upon  the 
small  crop;  the  air  that  furnished  a  large  proportion 
of  the  food  for  the  one  is  the  same  air  that  surrounded 
the  other;  the  rains  that  moistened  and  assisted  in 
the  solution  and  circulation  of  plant -food  for  the  one 
were  the  same  for  the  other.  Why,  then,  the  diflferenee 
in  results?  In  one  case  the  natural  agencies,  sun,  air 
and  water,  were  assisted  and  enabled  to  do  their 
maximum  work,  while  in  the  other,  they  were  pre- 
vented from  exercising  their  full  influence.  Physical 
conditions  of  soil  were  imperfect,  due  to  careless  plow- 
ing, seeding,  cultivation  and  cropping. 

In  other  words,  the   profit 'from  the  use  of   plant- 


THE    WASTEFUL    USE    OF   FERTILIZERS  37 

food  is  measured  to  a  large  degree  by  the  perfection  of 
soil  conditions,  which  are  entirely  within  the  power 
of  the  farmer  to  control.  The  production  possible 
from  a  definite  amount  of  plant -food  can  be  secured 
only  when  the  conditions  are  such  as  to  permit  its 
proper  solution,  distribution  and  retention  by  the  soil. 

The  fact  that  fertilizers  may  now  be  easily  secured, 
and  the  ease  of  application,  have  encouraged  a  care- 
less use,  rather  than  a  thoughtful  expenditure,  of  an 
equivalent  amount  of  money  or  energy  in  the  proper 
preparation  of  the  soil.  Of  course,  it  does  not  follow 
that  no  returns  are  secured  from  plant -food  applied 
under  unfavorable  conditions,  though  full  returns 
cannot  be  secured  under  such  circumstances.  Good 
plant -food  is  wasted,  and  the  profit  possible  to  be 
derived  is  largely  reduced. 

Again,  because  farming,  in  its  strict  sense,  is  the 
conversion  of  three  essential  elements  into  salable 
products,  the  time  to  apply  plant -food  must  be 
governed  largely  by  its  cost  and  the  kind  of  crop 
upon  which  it  is  applied. 


CHAPTER  m 

NITROGENOUS  FERTILIZERS 

Nitrogen  is  the  most  expensive  constituent  of  fer- 
tilizers, and,  all  things  considered,  it  is  one  of  the 
most  useful.  Nitrogen  exists  in  nature  as  a  compo- 
nent of  the  air,  and  though  quite  as  necessary  to 
vegetation  as  carbon  or  oxygen, — which  also  exist  in 
the  atmosphere,  and  which  are  readily  acquired  by 
all  plants, — all  plants  do  not  have  the  power  of  acquir- 
ing nitrogen  from  this  source.  This  power  seems  to 
be  limited  to  a  class  of  plants  called  Legurainosae,  to 
which  belong  the  various  clovers,  peas,  beans,  vetches, 
and  a  number  of  others.  The  important  farm  crops 
belonging  to  the  other  botanical  groups  of  plants 
obtain  their  nitrogen  largely,  if  not  altogether,  from 
the   soil. 

Vegetable  or  animal  matter  containing  nitrogen 
may  serve  as  a  source  of  nitrogen  to  plants,  though 
it  cannot  feed  them  with  this  element  to  anj^  extent 
until  it  decays  or  rots.  In  order  to  obtain  a  clear 
conception  of  the  use  of  nitrogen  as  a  fertilizer,  we 
should  understand  the  need  of  plants  for  it,  what  is 
meant  by  form  of  nitrogen,  and  the  sources  from 
which  the  various  forms  may  be  derived,  as  well  as 
the  relative  agricultural  or  crop -producing  value  of 
the   nitrogen   in   existing   commercial   forms. 

(38) 


FORMS    OF    NITROGEN  39 

WHAT    IS    MEANT    BY    FORM    OF    NITROGEN? 

Strictly  speaking,  form  of  nitrogen  has  reference 
to  its  combination  or  association  with  other  chemical 
elements,  though  sometimes  the  term  form  is  used 
to  indicate  rate  of  solubility,  which  also  measures 
to  some  degree  availability,  since  it  happens  that 
soluble  forms  of  nitrogen  are  really  more  available 
than  the  insoluble  forms,  though  neither  the  soluble 
nor  insoluble  forms  show  the  same  rate  of  availabil- 
ity; that  is,  a  pound  of  soluble  nitrogen  is  not  equally 
available  from  whatever  source  derived,  and  a  pound 
of  insoluble  from  one  source  may  be  much  more  avail- 
able than  a  pound  from  another.  The  form  in  which 
nitrogen  exists  in  vegetable  and  animal  matter  is 
called  the  "organic  form,"  because  it  is  associated 
with  other  constituents,  as  carbon,  hydrogen  and 
oxygen,  which  are  necessary  to  make  the  substances 
that  constitute  animal  or  vegetable  matter,  as  we  see 
them.  The  term  "organic,"  as  applied  to  nitrogen, 
covers  a  whole  series  of  substances,  and  does  not 
indicate  a  uniformity,  either  in  content  or  quality  of 
the  nitrogen,  as  is  the  case  with  distinct  chemical 
compounds;  hence,  associated  with  the  knowledge  of 
form  of  nitrogen,  when  it  exists  in  organic  products, 
must  be  a  knowledge  of  whether  the  material  contains 
a  very  considerable  amount  of  nitrogen,  and  whether 
it  is  likely  to  be  readily  changed,  and  thus  become 
available  as  food  for  plants. 

Any  nitrogenous  vegetable  or  animal  matter  may 
serve  as  a  fertilizer,  though   organic   nitrogen  in  com- 


40  FERTILIZERS 

mercial  fertilizers  is  usually  obtained  from  products 
relatively  rich  in  this  constituent,  and  it  is  only  these 
that  can  be  used  to  advantage  in  making  what  are 
known  as  "high-grade  fertilizers."  The  leading  ani- 
mal substances  of  this  class  are  now  mentioned. 

DRIED    BLOOD 

One  of  the  chief  products  from  which  organic 
nitrogen  is  derived  for  commercial  fertilizers  is  dried 
blood.  It  is  one  of  the  most  important,  because  it  is 
one  of  the  most  concentrated,  one  of  the  richest  in 
nitrogen  of  the  organic  nitrogenous  fertilizing  ma- 
terials, and  it  is  one  of  the  best,  since  its  phj'sical 
character  is  such  as  to  permit  of  its  very  rapid  decay 
in  the  soil  during  the  growing  season.  This  tendency 
to  rapid  decay  is  plainly  apparent,  when  we  remember 
that  blood  as  it  exists  in  the  animal  is  in  a  fluid 
form,  and  naturally  any  material  which  is  sufficiently 
finely  divided  to  permit  of  its  ready  flow,  and  is  not 
associated  with  any  hard  or  fibrous  material,  possesses 
characteristics  which  enable  a  rapid  breaking  down 
when  subjected  to  the  proper  temperature  and  mois- 
ture, conditions  which   promote   decay. 

Dried  blood  for  fertilizing  purposes  is  chiefly  ob- 
tained from  the  large  slaughtering  establishments,  and 
the  markets  recognize  two  distinct  kinds;  namely,  that 
which  is  red  and  that  which  is  black.  The  red  dried 
blood  results  from  the  careful  drying  of  the  fresh 
blood  with  hot  water,  at  which  temperature  it  does 
not  char,  nor  become  injured  in  quality.    When  dried 


HIOH-GRADE    NITBOGENOUS    MATERIALS  41 

at  a  higher  temperature,  and  by  other  methods,  it  is 
darker  in  color,  and  has  a  leathery  character,  is  less 
useful  in  the  arts,  and  is  slower  to  decay.  Red  blood, 
which  commands  the  highest  price,  is  reasonably  uni- 
form in  composition.  It  contains  from  13  to  14  per 
cent  of  nitrogen,  and  but  traces  of  phosphoric  acid — 
it  is  always  classified  as  "high-grade."  The  black  dried 
blood  is  of  a  lower  grade,  and  may  range  in  content 
of  nitrogen  from  6  to  12  per  cent ;  it  also  contains 
considerable  phosphoric  acid,  frequently  as  high  as  4 
per  cent.  Usually  the  lower  the  content  of  nitrogen,  the 
higher  the  content  of  phosphoric  acid ;  the  latter  is 
contained  in  the  impurities  (other  substances,  largely 
bone)  with  which  it  is  contaminated.  The  lower  grade 
blood  is  very  generally  used  in  the  manufacture  of 
fertilizers,  since  it  is  really  the  only  good  use  to  which 
it  may  be  put ;  the  high-grade  is  useful  for  other 
commercial  purposes. 

DRIED    MEAT    OR    MEAL,    AZOTIN,    AMMONITE,    OR 
ANIMAL    MATTER 

Dried  meat  or  meal,  azotin,  ammonite,  or  animal 
matter,  are  terms  applied  to  practically  the  same  pro- 
duct, though  produced  in  a  different  way.  This  ma- 
terial is  another  source  of  high-grade  organic  nitrogen. 
It  is  rich  in  the  constituent  element,  and  also  decays 
rapidly  in  the  soil.  When  relatively  pure,  it  contains 
as  high  as  13  or  14  per  cent  of  nitrogen,  and  thus  in 
this  respect  compares  very  favorably  with  blood.  The 
largest    supply  comes   from  rendering  establishments, 


42  FEBTILIZEBS 

where  the  different  portions  of  dead  animals  are  util- 
ized. These  are  subjected  to  treatment,  usually  dried 
and  extracted  with  steam,  for  the  purpose  of  securing 
the  fat,  though  formerly,  and  even  now,  a  large  por- 
tion of  this  product  is  obtained  from  the  beef  extract 
factories. 

HOOF    MEAL. 

Hoof  meal  is  a  reasonably  uniform  product,  rich 
in  nitrogen.  It  averages  as  high  as  12  per  cent,  and 
in  reference  to  availability  has  heretofore  been  classed 
with  low-grade  products.  In  recent  cultural  experi- 
ments, however,  the  results  indicate  that  it  is  much 
more  valuable  as  a  source  of  nitrogen  than  leather, 
wool  or  hair.  Commercially,  it  ranks  with  the  high- 
grade  products. 

DRIED    AND    GROUND    FISH,    OR'  FISH    GUANO 

This  product  is  obtained  from  two  sources:  first, 
from  the  offal,  largely  bones  and  skins,  of  fish  packing 
or  canning  houses;  and  second,  from  the  fish  pomace 
resulting  from  extraction  of  the  oil  from  the  men- 
haden. The  latter  product  is  richer  in  nitrogen  and 
is  more  uniform  in  character  than  the  wastes  from 
the  packing  houses.  Dried  ground  fish  from  this 
source  contains  from  7  to  8  per  cent  of  nitrogen,  and 
from  6  to  8  per  cent  of  phosphoric  acid.  The  former, 
owing  to  the  varying  proportions  of  bone,  skin  and 
flesh  contained  in  it,  varies  widely  in   its   content   of 


TANKAGE  43 

nitrogen.  Fish,  besides  affording  a  considerable  supply 
of  nitrogen,  is  also  regarded  as  a  good  source  of  this 
element,  ranking  in  availability  well  up  to  blood  and 
tankage,  and  is  largely  used  in  the  northern  coast 
states,  where  the  supply  is  reasonably  abundant. 

KING    CRAB 

King  crab  is  found  in  considerable  quantities 
along  the  Atlantic  coast,  and  is  not  only  used  directly 
as  a  fertilizer,  but  is  also  dried  and  ground  and  intro- 
duced into  commercial  mixtures.  It  is  a  highly  nitrog- 
enous product,  containing  in  the  dry  state  an  average 
of  10  per  cent,  with  traces  only  of  phosphoric  acid. 
It  also  possesses  a  high  rate  of  availability,  though 
information  on  this  point  is  derived  from  the  practical 
experience  of  farmers,  rather  than  from  actual  scien- 
tific test. 

TANKAGE 

Tankage  is  a  highly  nitrogenous  product,  and  con- 
sists chiefly  of  the  dried  animal  wastes  from  the  large 
abattoirs  and  slaughtering  establishments.  It  is  va- 
riable in  its  composition,  since  it  includes  the  otherwise 
unusable  parts  of  the  carcass,  as  bone,  tendons,  flesh, 
hair,  etc.  The  portions  of  this  from  the  different 
animals  not  only  vary  in  their  composition,  but  they 
are  used  in  varying  proportions,  which  naturally  re- 
sults in  an  extremely  variable  product.  What  is  known 
as  "concentrated  tankage,"  which  is  obtained  by  evap- 


44  FERTILIZERS 

orating  the  fluids  which  contain  certain  extractive 
animal  matter,  is  the  richest  in  nitrogen,  and  is  more 
uniform  in  character  than  the  others ;  and  because  of 
its  fineness  of  division  and  physical  character,  the 
nitrogen  contained  in  it  is  also  more  active  than  in 
the  other  forms.  Two  distinct  kinds  of  tankage  can, 
therefore,  be  obtained;  first,  concentrated  tankage, 
which  is  the  richer  in  nitrogen,  ranging  from  10  to  12 
per  cent,  and  which  contains  very  little  phosphoric 
acid;  and  second,  crushed  tankage,  which  is  of  several 
grades,  ranging  from  4  to  9  per  cent  nitrogen,  and 
from  3  to  12  per  cent  of  phosphoric  acid.  Products 
are  sometimes  sold  as  tankage,  which  contain  much 
more  than  the  maximum  of  phosphoric  acid  and  less 
than  the  minimum  of  nitrogen  here  given,  in  which 
case  they  are  to  be  classed  with  bone,  rather  than  with 
tankage.  Tankage  varies  so  much,  both  in  its  content 
of  phosphoric  acid  and  nitrogen,  that  in  the  trade  it  is 
always  sold  on  the  basis  of  its  composition.  The  per- 
centage of  nitrogen  and  phosphoric  acid  is  distinctly 
stated,  and  because  it  contains  very  considerable 
amounts  of  phosphoric  acid,  its  commercial  value  is 
not  wholly  based  on  its  content  of  nitrogen,  as  is  the 
case  with  dried  blood,  dried  meat,  and  concentrated 
tankage. 

GARBAGE  TANKAGE 

Garbage  tankage  is  a  name  given  to  a  product  now 
obtained  by  the  drying,  and  sometimes  partial  charring, 
of  the  garbage  of  cities.     It  usually  contains  variable 


LEATHER,     WOOL    AND    HAIR  45 

percentages  of  all  of  the  constituents,  though  chiefly 
valuable  for  the  nitrogen,  and  as  yet  cannot  be  classed 
among  the  standard  fertilizer  supplies,  because  of  its 
variability,  and  because  the  usefulness  of  the  con- 
stituents have  not  yet  been  determined. 

LOW-GRADE  NITROGENOUS  PRODUCTS 

Other  products  which  contain  a  high  content  of 
nitrogen  are  frequently  used.  These,  because  of  their 
low  rate  of  availability,  constitute  a  separate  and  dis- 
tinct class.  For  example,  horn  meal,  or  ground  horn, 
is  reasonably  uniform  in  its  composition  or  content  of 
nitrogen.  It  contains  as  high  as  10  or  12  per  cent  of 
nitrogen,  but  it  is  slow  to  decay  when  used  in  its 
natural  state,  and,  therefore,  is  not  regarded  as  an  eco- 
nomical source  of  this  element,  unless  it  can  be  ob- 
tained at  a  low  price. 

Leather  meal. — Leather  meal  is  another  product 
which  is  rich  in  nitrogen,  but  which  is  so  slow  to  decay 
that  its  use  in  the  natural  state  is  not  recommended. 
One  object  in  making  leather  is  to  render  it  resistant 
to  the  conditions  which  promote  decay,  and  ground 
leather  may  remain  for  years  in  the  soil  in  an  un- 
changed condition. 

Wool  and  hair  waste. — Wool  waste  and  hair  waste 
are  also  products  which  exist  in  considerable  quanti- 
ties, and  while  variable  in  composition,  are  frequently 
rich  in  nitrogen,  but  they  are  classed  with  leather 
because  of  their  slow  activity.  Their  mechanical  form, 
coarse  and  bulky,  makes  it  impossible  to  use  them  to 


46  FERTILIZERS 

advantage  in  the  manufacture  of  fertilizers  without 
previous  treatment.  The  use  of  these  materials,  un- 
treated, can  only  be  regarded  as  desirable  when  they 
may  be  obtained  at  a  very  low  cost.  When  dissolved 
with  acid,  or  treated  in  such  a  way  as  to  render  them 
more  immediately  available,  they  may  be  used  to  ad- 
vantage, though  the  cost  of  such  treatment  is  usually 
so  great  as  to  make  it  impossible  to  thus  improve  their 
form  and  still  be  able  to  compete  commercially  with 
the  other  nitrogenous  products. 

VEGETABLE    NITROGENOUS  PRODUCTS 

Cotton- seed  meal  is  one  of  the  best  of  the  vegetable 
nitrogenous  fertilizing  materials.  It  is  reasonably  con- 
centrated, and  decays  rapidly.  Tests  which  have  been 
made  show  that  it  ranks  with  blood  in  the  availability 
of  its  nitrogen.  Properly  prepared,  that  is,  when  free 
from  hulls,  this  product  contains  negfi'ly  7  per  cent  of 
nitrogen.  It  is  used  in  very  large  quantities,  particu- 
larly in  the  southern  states,  where  it  is  in  abundant 
supply.  It  is,  however,  a  most  excellent  cattle  feed, 
and  its  use  directly  as  a  fertilizer  will  be  reduced  in 
proportion  as  its  usefulness  for  this  purpose  is  more 
fully  appreciated. 

Linseed  meal  is  a  material  somewhat  similar  in 
character  to  cotton -seed  meal.  It  contains  on  the 
average  5.5  per  cent  of  nitrogen.  The  demand  for 
this  product  for  feeding  purposes  at  good  prices  makes 
it,  however,  an  expensive  source  of  nitrogen. 

Castor  pomace. — Castor  pomace,  the  waste  resulting 


NATURAL    GUANOS  47 

from  the  extraction  of  oil  from  the  castor  bean,  is  also 
a  valuable  nitrogenous  fertilizer.  It  contains,  on  the 
average,  6  per  cent  of  this  element,  and  decays 
rapidly  in  the  soil.  This  product  differs  from  the 
cotton-seed  and  linseed  meal,  in  that  it  is  not  useful 
as  a  cattle  food.  Practically  its  only  use  is  as  a 
fertilizer. 

NATURAL    GUANOS 

A  series  of  nitrogenous  products  which  constitute 
still  auother  separate  class,  consists  of  the  various 
natural  guanos.  These  were  formerly  a  very  large  and 
valuable  source  of  nitrogen,  though  at  the  present 
time  they  are  not  commercially  important,  owing  to 
the  practical  exhaustion  of  the  best  supplies.  Of  the 
guanos,  the  product  obtained  from  Peru,  or  from 
islands  on  the  coast  of  that  country,  is  the  richest  in 
nitrogen.  It  is  derived  almost  entirely  from  the  ex- 
crement of  sea  birds,  as  well  as  from  the  remains  of 
the  birds  themselves,  and  from  various  other  animals. 
The  composition  of  this  guano  is  of  a  very  complex 
character.  The  nitrogen  exists  largely  as  ammonia, 
combined  with  oxalates,  urates,  humates,  sulfates, 
phosphates,  carbonates,  and  to  some  extent  in  purely 
organic  forms.  In  these  forms  the  nitrogen  is  quickly 
available,  and  marvellous  results  are  obtained  from 
their  use. 

Other  guano  deposits  of  considerable  value,  though 
poorer  than  the  Peruvian,  are  found  farther  north  on 
the  coast  of    South  America,   as  well  as  upon  certain 


48  FERTILIZERS 

islands  on  the  southwest  coast  of  Africa,  Ichaboe 
guano,  for  example,  is  at  present  exported,  though  it 
is  a  fresh  deposit,  and  is  annually  collected  for  ship- 
ment. It  is  very  inferior  to  the  Peruvian  guano, 
containing  a  very  considerable  amount  of  insoluble 
matter.  At  the  present  time,  too,  we  have  "bat  guano," 
found  in  caves  in  Mexico  and  in  some  of  the  south- 
western states.  This  product  is  very  inferior  to  the 
Peruvian  guano  in  its  content  of  nitrogen,  though  the 
form  is  good,  a  considerable  portion  existing  as  nitrate. 
Owing  to  the  very  excellent  results  that  were  obtained 
from  the  early  use  of  guanos,  many  attempts  have 
been  made  to  improve  the  lower  grades  obtainable  at 
the  present  time,  by  the  addition  of  nitrogenous  matter 
of  a  higher  rate  of  availability.  These  rectified,  or 
fortified  guanos,  while  containing  nitrogen  in  good 
forms,  cannot  entirely  substitute  the  original  guanos, 
owing  to  the  impossibility  of  adding  forms  identical 
with  those  existing  in  the  natural  product.  That  is, 
the  total  content  of  nitrogen  in  a  rectified  guano  may 
be  the  same  as  in  the  genuine  product,  though  the 
special  forms  and  their  proportions  cannot  be  simulated. 
The  distinctive  value  of  the  natural  guanos  is  due  to 
the  fact  that  the  nitrogen  existed  in  a  number  of  dif- 
ferently soluble  compounds,  which  became  available  at 
different  times  in  the  soil,  and  thus  constantly  fed  the 
plant  with  this  element.  The  fact  that  nitrogen  guanos 
gave  such  good  results,  is  an  evidence  of  the  advan- 
tage of  introducing  different  forms  into  artificial 
mixtures. 

It  is  argued  that  because  of  the  very  great  value  of 


NATURAL    GUANOS  49 

guanos,  which  consist  very  largely  of  the  excrement 
of  fowls,  that  droppings  of  pigeons,  particularly,  and 
of  domestic  fowls  should  also  possess  a  high  value, 
and  for  this  reason  a  rather  fictitious  value  has  been 
fixed  upon  these  products.  These  products  differ  very 
materially  from  natural  guanos,  and  it  is  due  probably 
both  to  the  character  of  the  food  eaten  by  the  domestic 
fowl,  and  to  the  different  methods  by  which  the 
material  is  obtained.  The  birds  producing  the  guanos 
feed  largely  upon  fish,  a  highly  nitrogenous  food, 
resulting  in  an  excrement  richer  in  this  element  than 
that  from  the  domestic  bird,  feeding  largely  upon 
vegetable  matter ;  and,  besides,  the  former  were  accu- 
mulated in  a  hot,  dry  climate,  which  quickly  absorbs 
the  moisture  contained  in  the  fresh  droppings,  thus 
leaving  it  in  a  much  drier  state  than  is  the  case  with 
the  domestic  product. 

It  will  be  observed  from  the  foregoing  brief  de- 
scription of  the  chief  sources  of  organic  forms  of 
nitrogen,  that  a  very  wide  variation  occurs  both  in 
the  composition  or  content  of  nitrogen  in  these  pro- 
ducts, and  in  the  availability  of  their  nitrogen,  or 
rapidity  with  which,  under  similar  conditions,  it  is 
given  up  to  plants.  The  fact  that  a  substance  contains 
nitrogen  in  considerable  amounts  and  in  an  organic 
form,  then,  is  not  a  sufficient  guide  as  to  its  usefulness. 
Its  mechanical  condition,  or  physical  form,  must  also 
be  taken  into  consideration,  and,  other  things  being 
equal,  the  tougher  and  denser  the  substances,  the 
longer  the  time  required  to  deca}-,  and  hence  the  more 
slowly  will  the  material  feed  the  plant. 


50  FERTILIZEBS 


AMMONIA  COMPOUNDS 


As  already  stated,  nitrogen  does  not  feed  the  plants 
in  organic  forms ;  it  must  first  decay.  The  first  pro- 
duct of  the  decay  of  a  nitrogenous  organic  substance 
is  ammonia,  a  combination  of  two  elements,  hydro- 
gen and  nitrogen.  As  the  organic  animal  or  vege- 
table substance  which  contains  carbon,  hydrogen,  oxy- 
gen and  nitrogen  in  combination  breaks  up,  the  car- 
bon combines  with  part  of  the  oxygen  to  form 
carbonic  acid ;  part  of  the  hydrogen  also  combines 
with  oxygen  to  form  water,  and  the  nitrogen  combines 
with  hydrogen  to  form  ammonia.  Yet  even  in  this 
form,  plants  do  not  absorb  it  freely.  Ammonia  is  in 
a  better  form  than  the  organic  material,  because,  in 
the  first  place,  it  is  soluble  in  most  of  its  combina- 
tions with  other  substances,  and  is  thus  readily  dis- 
tributed in  the  soil,  and  in  the  second  place,  it  is 
very  liable  to  change.  That  is,  its  future  availability 
is  no  longer  dependent  upon  any  mechanical  or  phys- 
ical form;  every  portion  or  pound  of  ammonia  is  as 
good  as  any  other  portion  or  pound.  Ammonia, 
however,  does  not  occur  as  a  natural  product,  like 
the  organic  forms,  blood,  meat  and  fish.  Commercial 
forms  are  the  result  of  a  manufacturing  process,  and 
they  may  exist  as  distinct  chemical  substances,  as 
sulfate  of  ammonia,  in  which  case  the  ammonia  is 
combined  with  sulfuric  acid;  as  chlorid  of  ammonia, 
in  which  case  it  is  combined  with  hydrochloric 
acid ;  as  nitrate  of  ammonia,  in  which  case  it  is 
combined  with  nitric  acid ;    and  as   carbonate  of   am- 


SULFATE    OF   AMMONIA  51 

monia,   in  which    ease   it   is    combined   with    carbonic 
acid. 

Sulfate  of  ammonia  is  the  only  one  of  these  com- 
pounds which  can  be  now  obtained  at  a  sufficiently 
low  cost  to  encourage  its  use  as  a  fertilizer.  Sulfate 
of  ammonia  is  a  chemical  salt  which,  when  pure, 
contains  21.2  per  cent  of  nitrogen.  In  commercial 
forms,  however,  it  usually  contains  about  20  per  cent 
of  nitrogen,  and  even  this  makes  it  the  richest  in 
nitrogen  of  any  of  the  commercial  nitrogenous  pro- 
ducts. That  is,  every  ton  contains  400  pounds  of 
nitrogen,  and  is  thus  richer  by  60  pounds  per  ton 
than  nitrate  of  soda,  the  next  highest  grade  nitrog- 
enous product.  Sulfate  of  ammonia  is  obtained  from 
the  dry  distillation  of  animal  bone  in  the  manufacture 
of  bone-black,  from  the  distillation  of  coal  in  the 
manufacture  of  illuminating  gas,  and  from  coal  in 
the  manufacture  of  coke.  The  quantity  now  made  is 
increasing  annually,  largely  because  of  the  improved 
methods  used  in  the  manufacture  of  coke,  which  per- 
mit the  saving  of  the  ammonia.  The  cost  of  nitrogen 
in  this  form  is  likely  to  be  so  much  reduced  in 
future  as  to  encourage  its  very  considerable  use  by 
fertilizer  manufacturers.  Its  chief  advantages  are  that 
it  is  very  concentrated,  therefore  reducing  the  cost 
of  handling ;  it  is  always  in  the  same  form,  a  distinct 
and  definite  product,  thus  rendering  its  purchase  a 
safe  proceeding ;  and  it  is  very  quick  to  act,  thus 
making  it  a  very  useful  form,  especially  for  quick - 
growing  crops.  Its  physical  character  is  such  as  to 
permit  its  ready  distribution  in  a  mixture. 


52  FEBTILIZERS 

NITRATE     NITROGEN 

As  previously  stated,  neither  organic  nor  ammonia 
compounds  containing  nitrogen  are  capable  of  fully 
meetings  the  demands  of  plants  for  this  element.  The 
first,  or  organic  nitrogen,  must  pass  through  two 
changes,  first  to  ammonia,  and  then  to  nitrate,  and 
the  ammonia  must  change  to  a  nitrate.  The  nitrate  is 
directly  absorbed  by  plants,  and  the  larger  portion 
obtained  by  them  is  taken  up  in  this  form.  Hence, 
from  the  standpoint  of  availability,  nitrate  nitrogen 
must  be  regarded  as  the  most  useful  form.  Like 
ammonia,  too,  a  pound  of  it  is  as  good  as  any  other 
pound,  from  whatever  product  it  may  have  been  de- 
rived. It  is  a  relatively  concentrated  material ;  and 
as  it  is  perfectly  soluble,  it  readily  distributes  itself 
everywhere  in  the  soil  to  which  it  may  be  applied. 

Nitrate  of  soda. — Although  nitrogen  as  nitrate  is 
not  generally  distributed  as  a  natural  product,  vast 
deposits  of  crude  nitrate  of  soda  are  found  in  the 
rainless  districts  of  South  America.  These  crude  salts 
contain  from  4  to  10  per  cent  of  nitrogen,  which  are 
dissolved  and  re -crystallized  before  they  are  put  upon 
the  market,  in  order  to  remove  as  far  as  possible  the 
impurities  which  are  associated  with  them.  The  chem- 
ically pure  salt,  nitrate  of  soda,  contains  16.47  per  cent 
of  nitrogen,  and  the  commercial  article,  called  "Chili 
saltpeter,"  contains  from  15.5  to  16  per  cent.  The 
impurities  which  remain  in  it  consist  mainly  of  sodium 
chlorid,  or  common  salt,  which,  together  with  moisture, 
causes  a  lower  percentage  in  the  commercial  product. 


A  VAILABILITY    OF    NITROGEN  53 

THE    RELATIVE    AVAILABILITY    OF    THE    DIFFERENT 
FORMS    OF    NITROGEN 

From  this  discussion  of  the  kind  and  source  of 
nitrogenous  fertilizer  supplies,  it  is  shown  that  the 
form  of  the  nitrogen  is  an  important  factor  in 
determining  the  rate  at  which  the  plants  may  obtain 
it.  In  the  case  of  nitrate,  the  form  is  such  as  to 
enable  the  plants  to  take  it  up  immediately.  It  is, 
therefore,  theoretically  the  best,  because  as  soon  as 
it  comes  in  contact  with  the  roots,  it  is  absorbed  by 
them;  there  is  no  appreciable  time  required  to  enable 
the  element  to  get  into  a  condition  to  be  taken  up. 
Furthermore,  its  extreme  solubility  makes  it  possible, 
when  moisture  conditions  are  good,  to  reach  every 
portion  of  the  soil  in  which  the  roots  are  located,  so 
that  it  is  not  only  more  available  by  virtue  of  its  being 
in  the  right  form,  but  because  it  readily  goes  to  the 
place  where  the  plant  roots  are.  The  next  substance 
in  order  of  availability  is  ammonia,  and  the  rapid- 
ity with  which  ammonia  will  change  to  a  nitrate 
makes  it  under  many  circumstances  quite  as  useful. 
It  possesses,  too,  one  great  advantage  possessed  by 
the  nitrate,  that  of  being  soluble  in  water,  and  thus 
readily  distributing  itself  throughout  the  surface  soil. 
The  difference  in  usefulness  of  these  two  forms  seems 
to  depend  more  largely  upon  the  character  of  the 
season  than  upon  the  exact  form.  In  a  very  wet 
season  the  nitrate  is  less  useful,  because  liable  to  be 
washed  below  the  reach  of  the  roots,  or  lost  alto- 
gether,   and   in  a   dry   season  it   is  more  useful   than 


54  FERTILIZERS 

the  ammonia,  because  as  soon  as  it  is  in  solution  it  is 
capable  of  being  absorbed.  It  must  be  remembered, 
however,  that  these  two  forms  possess  the  further 
advantage  over  organic  forms,  that  they  are  definite 
chemical  compounds,  which  always  possess  the  same 
characteristics,  and  under  similar  conditions  they  always 
act  in  the  same  way.  If  nitrogen  is  purchased  as  am- 
monia, the  source  of  the  nitrogen  is  not  important; 
that  is,  whether  derived  in  the  manufacture  of  bone- 
black,  or  of  illuminating  gas,  or  coke,  if  it  is  ammonia, 
it  is  identical  in  its  character.  The  same  is  true  of 
nitrate — the  original  source  of  the  nitrogen  is  imma- 
terial. 

The  availability  of  organic  forms,  as  already  pointed 
out,  depends  upon  the  rapidity  with  which  they  will 
change  to  the  nitrate  form.  Such  products  as  dried 
blood,  dried  meat,  dried  fish  and  concentrated  tank- 
age change  rapidly,  and  are,  therefore,  good  forms, 
while  products  like  raw  leather  and  horn  meal  are 
very  slow  to  change. 

The  practical  point,  and  the  one  of  prime  impor- 
tance to  the  farmer,  is,  then,  to  know  how  to  estimate 
the  relative  value  or  usefulness  of  these  different  pro- 
ducts, what  is  the  rate  of  availability  as  compared 
with  nitrate,  and  thus  the  relative  advantage  of 
purchasing  the  one  or  the  other,  at  the  ruling  market 
prices.  Relative  values,  however,  cannot  be  assigned 
as  yet,  though  careful  studies  of  the  problem  have 
been  made,  chiefly  by  what  are  known  as  "vegetation 
tests,"  that  is,  tests  which  show  the  actual  amounts  of 
nitrogen  that  plants  can  obtain  from  nitrogenous  pro- 


TESTS    OF    A  VAILABILITT  55 

ducts  of  different  kinds,  when  they  are  grown  under 
known  and  controlled  conditions.  The  results  so  far 
obtained,  while  only  serving  as  a  guide,  indicate  that 
when  nitrate  is  rated  at  100  per  cent,  blood  and 
cotton  seed  meal  are  about  70  per  cent,  dried  and 
ground  fish  and  hoof  meal  65  per  cent,  bone  and 
tankage  60  per  cent,  and  leather  and  wool  waste  range 
from  as  low  as  2  per  cent  to  as  high  as  30  per  cent. 
These  figures  furnish  a  fair  basis  for  comparing  the 
different  materials,  when  used  for  the  same  purpose 
or  under  the  same  conditions.  If,  for  example,  the 
increased  yield  of  oats  due  to  the  application  of 
nitrate  of  soda  is  1,000  pounds,  the  yield  from  blood 
and  cotton -seed  meal  would  be  700  pounds,  the  yield 
from  dried  ground  fish  and  hoof  meal  would  be  650 
pounds,  from  bone  and  tankage  600  pounds,  and  from 
leather,  ground  horn,  and  wool  waste,  from  20  to  300 
pounds. 

Conditions    Which   Modify   Availability 

These  figures  alone  are,  however,  not  a  sufficient 
guide  as  to  the  kinds  to  buy  under  all  conditions, 
since  the  usefulness  of  the  different  forms  are  again 
dependent  upon  such  other  conditions  as  the  kind  of 
crop,  the  season,  and  the  object  of  the  application. 
The  kind  of  crop  is  an  important  factor,  since  certain 
crops  grow  and  develop  quickly,  while  others  grow  for 
a  comparatively  long  period;  the  season, 'because  the 
changes  from  organic  forms  to  ammonia,  or  nitrate, 
only  take  place  when  the  temperature  reaches  37°  F., 


56  FERTILIZERS 

and  when  in  addition  sufficient  moisture  is  present. 
Hence,  a  material  which  might  give  excellent  results 
when  applied  to  a  crop  that  grows  through  a  long 
period  in  a  climate  where  the  season  is  very  warm 
and  moist,  might  be  very  unsatisfactory  where  the 
season  is  short,  cold  and  dry.  These  are  a  few  of 
the  conditions  which  modify  the  rate  of  the  decay  of 
the  same  material. 

The  object  of  the  application  should  also  be  taken 
into  consideration.  The  rate  of  the  feeding  of  the 
plant  with  nitrogen  in  organic  forms  is  measured  by 
the  rate  of  decay  of  the  organic  material  containing 
it,  while  when  nitrate  is  used,  its  feeding  is  direct. 
The  result  is  really  a  sort  of  feeding  of  the  soil  in 
the  one  case,  and  a  direct  feeding  of  the  plants  in  the 
other.  Where  the  purpose  is  to  get  the  largest  pro- 
portionate increase  in  crop  from  the  least  amount 
applied,  either  the  nitrate,  or  the  ammonia,  or  the 
more  active  of  the  organic  forms,  would  be  likely  to 
give  the  best  returns.  Whereas,  if  the  object  to  be 
attained  is  not  so  much  a  large  increased  crop  as  it 
is  increase  in  the  future  productive  capacity  of  the 
soil  in  respect  to  this  element,  the  slower-acting  ma- 
terials will  often  answer  the  purpose  quite  as  well  as 
the  use  of  the  more  active  nitrate  form,  as  in  this 
form  no  insoluble  combinations  are  formed,  the 
nitrate  is  freely  movable,  and  if  the  plants  do  not 
absorb  it,  and  heavy  rains  come,  the  water  contain- 
ing the  nitrate  is  carried  through  the  soil  into  the 
drains  and  the  nitrogen  lost.  The  disadvantage  of 
the  nitrate  is,  then,  that  there  is  a  greater  possibility 


CONDITIONS    WHICH   MODIFr   A  VAILABILITY    57 

of  loss  from  its  use  than  from  the  use  of  materials 
which  are  either  insoluble,  or  which  are  readily  ab- 
sorbed. The  ammonia,  while  perfectly  soluble,  is  fixed 
by  the  other  substances  in  the  soil,  and  is  not,  there- 
fore, readily  leached  out,  though  if  heavy  applications 
are  made  the  possibility  is  increased,  because  of  the 
rapid  change  of  the  ammonia  into  the  nitrate  form. 
In  the  case  of  organic  materials,  the  losses  from 
leaching  are  seldom  worthy  of  consideration  in  good 
practice,  since  an  appreciable  time  is  required,  even 
in  the  case  of  the  best  forms,  to  change  all  of  the 
nitrogen  into  ammonia,  and  then  to  a  nitrate ;  while 
in  the  case  of  the  poorer  forms,  still  more  time  is 
necessary  to  cause  the  change,  and  losses  are  not 
liable  to  occur.  In  the  making  up  of  fertilizers,  all 
of  these  considerations  should  be  carefully  balanced, 
and  it  is  the  practice  on  the  part  of  many  manufac- 
turers to  use  a  part  of  each  of  the  three  forms,  so 
that  a  continuous  feeding  of  the  plant  may  be  in- 
sured. Therefore,  while  the  fact  remains  that  fer- 
tilizers containing  only  the  one  form  may  not  be  the 
poorest,  the  chances  are  that  those  which  contain  all 
forms  are  likely  to  give   more   satisfactory  results. 


CHAPTER  IV 

PHOSPHATES— THEIB   SOURCES,    COMPOSITION  AND 
RELATIVE    VALUE 

Many  fanners  apply  the  term  "  phosphate "  to  all 
manufactured  fertilizers,  without  regard  to  the  kind 
and  character  of  the  fertilizing  constituents  con- 
tained in  them.  The  term  "phosphate"  should  only 
be  applied  to  materials  which  contain  phosphoric 
acid,  and  it  does  not  necessarily  imply  that  the 
phosphoric  acid  is  in  an  available  form.  The  term 
"superphosphate"  implies  that  the  phosphoric  acid 
contained  in  the  material  is  available.  The  phos- 
phates constitute  a  class  of  products  from  which 
superphosphates  are  made,  and  which  are  used  in  the 
manufacture  of  fertilizers  that  contain  immediately 
useful  or  available  phosphoric  acid.  The  following 
discission  of  phosphates  is  quoted  from  the  author's 
"  First  Principles  of  Agriculture  : "  * 

The  phosphoric  acid  in  artificial  manures  is  derived 
from  compounds  called  "phosphates."  In  phosphates 
the  phosphoric  acid  is  united  with  lime,  iron  and 
alumina,  forming  phosphates  of  lime,  iron  and 
alumina,    as    the    case    may  be.     The    phosphates    of 


*«First  Principles  of  AKricn]ture."  Silver,  Burdett  &  Co.,  Boston,  1896.  The 
quotation  comprises  the  entire  discussion  preceding  "Phosphates  as  Sources  of 
Phosphoric  Acid  to  Plants," except  "Bone  Tankage"  and  "Tennessee  Phosphate." 

(58) 


PHOSPHATE    OF    LIME  59 

lime  are  better  calculated  for  the  purpose,  and  are, 
therefore,  used  more  largely  than  any  other  as  a 
source  of  phosphoric  acid,  in  the  manufacture  of 
artificial   manures. 

The  phosphates  available  for  this  purpose  are  not, 
however,  pure  salts,  but  exist  in  combination  either 
with  organic  substances,  or  with  minerals,  or  both, 
the  content  of  phosphoric  acid  and  its  combination 
with  other  substances  determining  the  usefulness  of 
the  phosphate  to  the  manure -maker. 

The  phosphoric  acid  in  these  materials  is  soluble 
with  difficulty  in  the  soil  water ;  and  hence  in  their 
original  condition,  or  in  the  crude  raw  forms,  they 
give  up  this  element  in  proportion  as  they  decompose 
or  decay  in  the  soil.  Those  in  combination  with 
organic  substances,  either  animal  or  vegetable,  are, 
as  a  rule,  more  quickly  useful  as  a  source  of  phos- 
phoric acid  than  those  composed  entirely  of  mineral 
constituents. 

PHOSPHATE  OP  LIME,  OR  BONE  PHOSPHATE  — 
ANIMAL  BONE 

The  bones  of  animals  are  the  chief  source  of  phos- 
phates that  exist  in  combination  with  organic  matter, 
and  were  for  a  long  time  the  main  source  for 
manurial   purposes. 

Bone  consists  chiefly  of  three  classes  of  sub- 
stances ;  viz.,  moisture,  organic  matter,  containing 
nitrogenous  and  fatty  matter,  and  phosphate  of  lime, 
or    bone    phosphate  —  the    proportion,    particularly   of 


00  FBUTILIZERS 

the  nitrogen  and  phosphoric  acid,  depending  upon 
the  kind  of  bone  and  the  method  of  its  treatment. 

Bone  from  the  same  kind  of  animal  differs  in 
composition  according  to  the  age  of  the  animal  and 
its  location  in  the  body.  In  a  general  way,  the 
younger  the  animal  the  softer  the  bone,  the  poorer  in 
phosphate  of  lime  and  the  richer  in  nitrogen ;  the 
older  the  animal,  the  richer  in  phosphate  of  lime  and 
the  poorer  in  nitrogen.  The  large  and  hard  thigh 
bones  of  an  ox,  for  instance,  differ  in  composition 
from  the  softer  and  more  porous  bones  of  other  parts 
of  the  body. 

The  phosphate  of  lime  of  the  harder  bones  is 
dense  and  compact ;  that  from  the  softer  bone  is 
more  open  and  porous.  The  chief  cause  of  variation 
in  the  composition  of  bones  used  as  manure,  how- 
ever, is  due  to  the  treatment  they  receive.  This  is 
recognized  by  manufacturers  and  dealers,  and  differ- 
ent names  of  brands  are  used  to  indicate  the  method 
of  manufacture  or  treatment.  As  applied,  however, 
they  do  not  always  correspond  to  the  methods  of 
treatment. 

Raw  Bone 

The  term  "raw  bone"  is  properly  applied  to  bone 
that  has  not  suffered  any  loss  of  its  original  con- 
stituents in  the  processes  of  its  manufacture,  and  is 
for  this  reason  highly  regarded  by  farmers,  who 
believe  that  it  is  purer  than  any  other  form.  This  is 
true  in  a   large  measure,  though   the   fact   that   it   is 


ANIMAL   BONE  61 

raw  bone  is  not  altogether  an  advantage  from  the 
standpoint  of  usefulness.  Raw  bone  too  often  con- 
tains considerable  fatty  matter,  which  makes  it  a  diffi- 
cult process  to  grind  it  fine,  and  which  also  has  a 
tendency  to  retard  the  decay  of  the  bone  in  the  soil. 
A  considerable  amount  of  fat  also  reduces  propor- 
tionately the  percentage  of  the  valuable  constituents, 
phosphoric  acid  and  nitrogen.  Good  raw  bone,  free 
from  meat  and  excess  of  fat,  should  contain  on  the 
average  22  per  cent  of  phosphoric  acid  and  4  per  cent 
of  nitrogen. 

Fine   Bone 

The  trade  terms  "bone  meal,"  "bone  dust,"  and 
"fine  bone,"  are  used  to  indicate  mechanical  condi- 
tion, or  fineness  of  division,  and  do  not  refer 
especially  to  composition.  These  names  should  not 
be  taken  as  indicating  the  fineness  without  personal 
examination,  since  frequently  the  products  do  not,  in 
this  respect,  correspond  to  the  name.    . 

Boiled  and   Steamed  Bone 

The  larger  portion  of  the  bone  used  as  manure 
has  been  boiled  or  steamed  for  the  purpose  of  freeing 
it  from  fat  and  nitrogenous  matter,  both  of  which 
are  products  valuable  for  other  purposes.  The  fat  is, 
of  course,  of  no  value  as  a  manure,  and  its  absence 
is  an  advantage.  The  nitrogen,  while  useful  as  a 
manure,  is  extracted  chiefiy  for  the  purpose  of  making 
glue  and  gelatine. 


62  FERTILIZERS 

By  boiling  or  steaming,  the  bone  suffers  a  loss  of 
its  original  constituents,  the  chief  result  of  which  is 
to  change  the  proportions  of  the  nitrogen  and  phos- 
phoric acid  contained  in  it.  Steamed  or  boiled  bone 
contains  more  phosphoric  acid  and  less  nitrogen  than 
raw  bone,  and  is  also  more  variable  in  composition, 
the  relative  percentage  of  these  constituents  depending 
upon  the  degree  of  steaming  or  boiling  to  which  the 
bone  has  been  subjected. 

Bone  that  has  been  used  for  the  purpose  of 
making  glue,  where  the  chief  object  is  to  extract  the 
nitrogenous  matter,  contains  from  28  to  30  per  cent 
of  phosphoric  acid  and  from  1%  to  1%  per  cent  of 
nitrogen.  The  steaming  of  bone,  particularly  when 
conducted  at  high  pressure,  also  exerts  a  favorable 
effect  upon  the  physical  and  mechanical  character  of 
the  bone.  It  destroys  its  original  structure,  makes 
it  soft  and  crumbly,  and  often  reduces  it  to  a  finer 
state  of  division  than  can  be  readily  accomplished  by 
grinding ;  and,  since  it  is  also  free  from  fat,  and  is 
finer,  it  is  more  directly  useful  as  a  source  of  phos- 
phoric acid  to  plants  than  purer  raw  bone. 

In  some  cases,  the  fat  is  extracted  from  bone  by 
means  of  such  solvents  as  petroleum  or  benzine. 
These  methods  of  extracting  the  fat  have  the  ad- 
vantage of  increasing  the  relative  proportion  of 
the  nitrogen,  this  element  not  being  attacked  by 
the  solvents.  The  more  complete  extraction  of  the 
fat  and  moisture  by  these  methods  also  aids  in 
the  final  preparation  of  the  bone  by  grinding.  Bone 
prepared    in    this    way    frequently    contains    as    high 


TANKAGE  63 

as  6  per  cent  of  nitrogen  and  20  per  cent  of  phos- 
phoric acid. 

The  nature  and  composition  of  animal  bone  is 
such  as  to  make  it  a  valuable  source  of  phosphoric 
acid ;  and,  while  it  is  largely  used  with  nitrogenous 
and  potassic  materials  in  the  manufacture  of  artificial 
manures,  its  best  use  is,  perhaps,  in  the  fine  ground 
form,  particularly  for  soil  improvement  and  for  slow- 
growing  crops. 

Phosphoric  acid  applied  in  this  form  gradually 
gives  up  nitrogen  and  phosphoric  acid  to  the  plant ; 
and  its  physical  and  chemical  characteristics  are  such 
that  it  forms  in  the  soil,  during  the  growing  season, 
no  compounds  more  insoluble  than  the  bone  itself. 
Of  all  the  phosphatic  materials  available  as  manure, 
bone  is  the  only  one  that  is  now  used  to  any  extent 
without  further  treatment  than  simple  grinding. 

Bone    Tankage 

As  already  intimated  in  the  discussion  of  nitrog- 
enous materials,  certain  products  valuable  for  nitro- 
gen also  contain  considerable  amounts  of  phosphoric 
acid.  Among  these,  tankage  is  the  most  important, 
and  six  definite  grades  are  now  recognized  in  the 
trade  —  the  richest  containing  as  high  as  18  to  19  per 
cent  of  phosphoric  acid,  or  equivalent  to  40  per  cent 
bone  phosphate ;  the  second  containing  16  per  cent 
phosphoric  acid,  equivalent  to  35  per  cent  of  bone 
phosphate ;  the  third  containing  13%  per  cent  of 
phosphoric  acid,  or  equivalent  to  30  per  cent  of  bone 


64  FUBTILIZEBS 

phosphate ;  the  fourth,  11%  per  cent  of  phosphoric 
acid,  or  equivalent  to  25  per  cent  of  bone  phosphate ; 
the  fifth,  9  per  cent  phosphoric  acid,  or  equivalent  to 
20  per  cent  bone  phosphate,  and  the  sixth  contain- 
ing about  ^  per  cent  phosphoric  acid,  or  equivalent  to 
15  per  cent  bone  phosphate. 

It  will  be  observed  that  certain  grades  of  tankage 
approach  the  composition  of  bone  in  their  content  of 
phosphoric  acid ;  the  nitrogen  increases  as  the  phos- 
phoric acid  decreases,  as  already  pointed  out  in  the 
discussion  of  nitrogenous  materials.  Since  tankage 
is  made  from  the  residue  remaining  in  the  tanks 
used  for  boiling  cattle  heads,  feet,  clippings,  and  other 
refuse  animal  matter,  it  may  be  classed  with  boiled 
bone  in  reference  to  the  quality  of  its  phosphoric 
acid.  Its  agricultural  value  is  further  modified  by  the 
fineness  to  which  it  is  ground ;  it  is  frequently  sub- 
stituted for  bone  in  the  manufacture  of  fertilizers, 
where  phosphate  derived  from  bone  is  regarded  as  an 
important  constituent  of  the  mixture  or  brand. 

Other    Organic  Products 

There  are  also  other  products  which  should  not 
be  disregarded  in  a  discussion  of  phosphates,  though 
because  of  their  content  of  other  constituents  they  are 
primarily  valued  for  them,  rather  than  for  the  phos- 
phoric acid.  A  good  example  is  the  dried  ground 
fish,  which  often  contains  as  high  as  8  per  cent  of 
phosphoric  acid,  or  an  equivalent  of  17  to  18  per  cent 
of   bone  phosphate  of   lime.      The  phosphoric  acid  in- 


BONE-BLACK  65 

dried  fish  is  frequently  more  available  than  in  other 
organic  forms,  owing  to  the  fact  that  in  the  drying 
of  the  scrap  it  is  often  necessary  to  add  sulfuric  acid 
to  prevent  putrefaction.  On  the  average,  more  than 
one -half  of  the  total  phosphoric  acid  in  this  product 
is  in  an  available  form. 

The  phosphoric  acid  contained  in  other  nitrogenous 
products,  as  cotton -seed  meal  and  castor  pomace, 
while  not  large,  is  of  some  importance,  as  it  is  rela- 
tively more  available  than  in  raw  bone  or  in  tankage. 

Bone-hlacJc,  or  Animal    Charcoal 

This  material  becomes  an  important  source  of 
phosphoric  acid  for  artificial  manures,  after  it  has 
served  its  chief  and  first  purpose  in  clarifying  sugar. 
In  making  bone-black,  only  the  best  bones  are  used ; 
they  are  cleaned  and  dried,  and  placed  in  air-tight  ves- 
sels, and  heated  until  all  volatile  matter  is  driven  off; 
the  resultant  product,  which  retains  in  part  the  original 
form  of  the  bone,  is  then  ground  to  a  coarse  powder ; 
it  then  becomes  a  bone  charcoal,  consisting  chiefly  of 
carbon  and  phosphate  of  lime,  though  also  containing 
small  amounts  of  magnesia  and  carbonate  of  lime. 

Bone-black,  as  received  from  the  refineries,  con- 
tains the  impurities  gathered  there,  consisting  chiefly 
of  vegetable  matter  and  moisture.  It  is  somewhat 
variable  in  composition,  containing  from  32  to  36 
per  cent  of  phosphoric  acid  and  a  small  amount  of 
nitrogen.  It  decays  slowly  in  the  soil,  and  is  not  now 
used  to  any  extent  directly  as  a  manure. 


66  FERTILIZERS 

Bone- Ash 

Bone -ash  is  an  excellent,  though  not  large,  source 
of  phosphoric  acid.  It  is  exported  in  considerable 
quantities  from  South  America,  where  the  bones  are 
burned  and  the  bulk  reduced,  in  order  to  facilitate 
transportation.  It  does  not  contain  nitrogen,  and  is 
more  variable  in  composition  than  bone-black,  though 
usually  somewhat  richer  in  phosphate  of  lime.  Good 
samples  contain  from  27  to  36  per  cent  of  phos- 
phoric acid. 

Bones  themselves,  and  the  phosphates  derived 
from  bones,  constitute  a  class  differing  from  other 
phosphates  used  in  making  manures,  in  that  they  are 
derived  directly  from  organic  materials  and,  as  a 
class,  they  possess  characteristics,  due  to  this  fact, 
which  render  them  more  useful  than  those  derived 
from   purely  mineral   sources. 

MINERAL     PHOSPHATES 

These  constitute  a  class  of  products  differing  from 
those  of  immediate  or  recent  animal  origin  mainly  in 
the  fact  that  they  are  not  combined  with  organic  mat- 
ter, and  are  more  dense  and  compact  in  their  struc- 
ture. They  occur  in  several  different  forms,  and  are 
procured  from  distinct  sources. 

South    Carolina  RocJc   Phosphates 

These  are  found  both  on  the  land  and  in  the  beds 
of  rivers  in  the  vicinity  of  Charleston,  S.  C,  and  are 


SOUTH    CAROLINA    ROCK   PHOSPHATES  67 

sometimes  called  "Charleston  phosphates."  The  de- 
posits vary  in  thickness  from  one  to  twenty  feet, 
through  which  the  phosphate  is  distributed  in  the 
form  of  lumps  or  nodules,  ranging  in  weight  from  an 
ounce  to  over  a  ton.  These  nodules  are  irregular, 
non- crystalline  masses,  often  full  of  holes,  which  con- 
tain clay  or  other  non-phosphatic  materials.  That 
obtained  from  the  river  is  called  "river  phosphate," 
or  "river  rock;"  and  that  from  the  land,  "land  phos- 
phate," or  "land  rock."  The  two  varieties  do  not 
differ  materially  in  composition,  particularly  in  the 
content  of  phosphoric  acid. 

The  rock  contains  from  26  to  28  per  cent  of  phos- 
phoric acid.  Its  uniformity,  in  connection  with  the 
fact  that  it  contains  but  small  percentages  of  com- 
pounds of  iron  and  alumina,  minerals  which  prevent 
its  best  use  by  the  manufacturer,  make  it  a  highly 
satisfactory  source  of  phosphoric  acid. 

The  river  rock  is  secured  by  dredging  ;  that  from 
the  land  is  largely  dug.  In  either  case  it  is  washed 
to  remove  the  adhering  matter,  and  then  dried,  when 
it  is  ready  for  grinding  or  shipment.  South  Carolina 
rock  phosphate,  when  very  finely  ground,  is  called 
"floats."  It  is  sometimes  used  upon  the  land  in  this 
form,  and  when  used  for  certain  crops,  as  turnips,  for 
example,  and  on  certain  soils,  notably  those  wet  and 
heavy  and  rich  in  vegetable  matter,  very  satisfactory 
returns  are  obtained. 

These  deposits  were  first  worked  in  1868,  though 
the  presence  of  phosphate  at  this  point  was  known  at 
a  much  earlier  date. 


68  FERTILIZERS 

Florida  Phosphates 

The  presence  of  phosphate  iu  commercial  quanti- 
ties in  Florida  was  discovered  in  1888,  since  which 
time  very  great  progress  has  been  made  in  developing 
the  deposits.  The  deposits  occur  in  a  number  of 
forms,  —  first,  "soft  phosphate,"  a  whitish  product, 
somewhat  resembling  clay,  and  largely  contaminated 
with  it;  second,  "pebble  phosphate,"  consisting  of 
hard  pebbles,  occurring  both  in  river  beds  and  upon 
the  land,  and  mixed  with  other  materials  ;  and  third, 
"rock,"  or  "bowlder  phosphate,"  which  occurs  in  the 
form  of  stony  masses  or  bowlders,  both  large  and 
small.  These  three  forms  also  differ  widely  in  com- 
position, both  in  reference  to  their  content  of  phos- 
phoric acid  and  in  respect  to  the  presence  of  other 
minerals. 

The  soft  phosphate  is  the  poorest  in  phosphoric 
acid.  It  is  easily  prepared,  and  is  largely  used  directly 
upon  the  land.  It  is  also  the  most  variable  in  com- 
position, ranging  from  18  to  30  per  cent.  The  pebble 
rock  is  also  variable  in  composition,  though,  when 
washed  free  of  sand  and  claj',  it  is  richer  iu  phos- 
phoric acid  than  the  soft  variety.  Good  samples  con- 
tain as  high  as  40  per  cent  and  over  of  phosphoric 
acid.  The  bulk  of  the  "Florida  phosphate"  is  be- 
lieved to  exist  in  the  pebble  form. 

The  rock  or  bowlder  phosphate,  though  apparently 
much  less  in  amount,  is  more  uniform  in  composition, 
and  is  much  richer  than  either  of  the  other  forms. 
The   clean,    dry  bowlder   phosphate   often  contains   as 


OTHER    MINERAL    PHOSPHATES  69 

high  as  40  per  cent  phosphoric  acid,  far  exceeding  in 
richness  the  South  Carolina  rock  superphosphate. 

Canadian   Apatite 

This  material  is  a  crystallized  rock  of  true  mineral 
origin,  and  occurs  associated  to  a  greater  or  less  ex- 
tent with  other  materials.  It  is,  therefore,  not  uni- 
form in  character,  the  phosphoric  acid  varying 
according  to  the  amount  of  the  other  substances 
present. 

It  is  mined  in  the 'provinces  of  Quebec  and  Onta- 
rio, and  separated  into  various  grades  at  the  mines. 
The  mining  is  expensive,  and  the  necessity  for  grad- 
ing in  addition  makes  the  cost  of  production  propor- 
tionately high.  The  highest  grade  of  this  phosphate 
is  very  pure,  containing  40  per  cent  of  phosphoric 
acid. 

Tennessee   Phosphate 

The  phosphate  deposits  in  Tennessee  were  discov- 
ered in  November,  1894,  since  which  time  they  have 
been  exploited  and  a  rapid  development  made.  This 
phosphate  differs  from  the  phosphate  of  South  Caro- 
lina and  Florida  in  that  it  does  not  exist  as  nodules, 
pebbles  or  bowlders,  but  in  veins  and  pockets,  and, 
therefore,  does  not  need  to  be  washed  and  dried 
previous  to  its  treatment.  While  the  phosphates  from 
the  various  deposits  are  not  uniform  in  their  com- 
position, it  is  possible  to  secure   large  quantities  that 


70  FERTILIZERS 

equal  or  exceed  30  to  32  per  cent  of  phosphoric  acid, 
or  70  per  cent  or  over  of  bone  phosphate,  and  that 
are  relatively  free  from  deleterious  substances,  thus 
making  them  not  only  a  rich  but  a  valuable  source 
of  supply  for  the  manufacturers  of  superphosphates. 

Iron   Phosphate,    or   Thomas   Phosphate  Powder 

This  is  a  waste  product  from  the  manufacture  of 
steel  from  phosphatic  iron  ores,  by  what  is  known 
as  the  "basic  process."  It  is  sold  under  several 
names,  as  "  Thomas  phosphate  meal,"  "  phosphate 
slag,"  "basic  slag,"  and  "odorless  phosphate."  It 
is  produced  in  large  quantities  in  England,  France 
and  Germany,  and  in  those  countries  is  not  only  one 
of  the  cheapest  sources  of  phosphoric  acid,  but  is 
regarded  as  a  very  valuable  product.  It  contains 
from  15  to  20  per  cent  of  phosphoric  acid  in  the 
form  of  phosphate  of  lime,  in  connection  with  large 
amounts  of  lime  and  oxide  of  iron.  It  is  used  almost 
altogether  in  the  form  of  a  fine  powder,  since  it  is 
not  suitable  for  the  purposes  of  the  manufacturer. 

Phosphatic    Ouanos 

Previous  to  the  discovery  of  the  phosphates  in 
South  Carolina,  these  guanos  were  a  very  important 
source  of  phosphoric  acid.  They  are  now  but  little 
used  in  this  country.  They  are  obtained  from  the 
rainless  districts  of  the  world,  chiefly  from  the  islands 
bordering  the  coast  of  South  America  and  from  the 
West   Indies.     They  are  derived  from   the   excrements 


PE08PHATDS    AS   FERTILIZERS  71 

of  birds,   and  frequently  include   considerable   organic 
matter  containing  nitrogen. 

The  Peruvian  guano  of  earlier  times  was  particu- 
larly rich  in  the  best  forms  of  nitrogen.  The  purely 
phosphatic  guanos  are  rich  in  phosphoric  acid,  and  are 
excellent  materials.  Like  the  iron  phosphate,  they  are 
not  suitable  for  the  manufacture  of  artificial  manures. 

PHOSPHATES  AS  SOURCES  OP  PHOSPHORIC  ACID 
TO  PLANTS 

The  phosphates  mentioned  constitute  what  are  called 
"raw  materials,"  and,  with  the  exception  of  bone,  are 
not  largely  used  directly,  or  without  further  treatment 
to  render  the  phosphoric  acid  more  soluble,  and  thus 
more  immediately  available  to  plants.  As  already 
stated,  the  phosphoric  acid  in  them  becomes  food  ih 
proportion  to  the  rapidity  of  decay,  which  is  influenced 
both  by  the  character  of  the  material  and  the  fineness 
of  its  division.  Fine  materials,  too,  permit  of  a  more 
even  distribution,  thus  bringing  more  particles  of 
phosphate  in  contact  with  the  roots  of  plants. 

As  already  stated,  a  phosphate  is  a  substance  in 
which  the  phosphoric  acid  is  combined  with  lime,  iron 
or  alumina.  The  phosphates  of  lime  are  the  only  ones 
that  are  used  to  any  extent  in  the  manufacture  of  arti- 
ficial fertilizers.  The  phosphoric  acid  contained  in 
animal  bone  is  in  the  form  of  phosphate  of  lime, 
hence  the  term  "bone  phosphate  of  lime"  has  been 
applied  to  all  phosphates  that  contain  their  phosphoric 
acid    as   phosphate    of    lime.     In  fact,    statements    of 


72  FERTILIZERS 

analysis  of  iron  and  alumina  phosphates  are  frequently- 
expressed  in  terms  of  phosphate  of  lime.  That  is, 
the  content  of  phosphoric  acid  is  stated  as  equivalent 
to  a  certain  percentage  of  bone  phosphate,  the  term 
expressing  the  total  amount  of  combined  phosphoric 
acid;  as,  for  example,  a  bone  which  contains  20  per 
cent  of  phosphoric  acid,  which  is  the  average  content 
in  good  bone,  is  equivalent  to  43.60  per  cent  of  phos- 
phate of  lime. 

All  phosphates  are  insoluble  in  water,  but,  as 
phosphates,  they  are  not  capable  of  feeding  the  plant 
directly;  they  must  first  decay.  Hence,  the  useful- 
ness of  a  phosphate  depends  upon  the  rate  of  decay, 
or  time  required  to  change  to  such  a  form  as  to  be- 
come available  to  the  plant.  The  rapidity  with  which 
a  phosphate  will  feed  the  plant  depends  upon  a  num- 
ber of  conditions,  chief  among  which  are,  first,  the 
character  of  the  substance  itself;  second,  the  fine- 
ness of  its  division  ;  third,  the  character  of  the  soil 
to  which  it  is  applied;  and  fourth,  the  kind  of  crop 
for  which  it  is  used. 

The  Influence   of  Source   of  Phosphate    Upon 
Availability 

The  chief  point  to  be  observed  in  the  first  case, 
is  whether  the  substance  is  animal  or  vegetable,  or 
whether  it  is  mineral.  Phosphates  of  immediate 
animal  or  vegetable  origin  decay  more  rapidly  than 
purely  mineral  phosphates,  because  of  the  greater 
tendency  of   the  organic  matter  with  which   the  phos- 


AVAILABILITY    OF    PHOSPHATES  73 

phate  is  associated  to  respond  to  the  action  of  the 
natural  agencies  which  cause  decay.  A  bone,  for 
example,  if  kept  in  a  suitable  condition  of  moisture 
and  warmth,  will  soon  begin  to  rot,  the  rotting 
affecting  not  only  the  animal  matter,  but  more  or 
less  the  phosphatic  matter  with  which  it  is  so 
closely  identified,  the  fermentation  primarily  attack- 
ing the  organic  substances,  but  exercising  a  greater 
or  less  solvent  effect  upon  the  phosphates. 

In  the  case  of  the  mineral  substances,  the  rate  of 
decay  is  usually  much  slower,  because  there  is  no 
organic  fermentation.  The  material  changes  or  is 
broken  up  only  by  virtue  of  the  action  of  the  natural 
solvents,  air  and  water,  and  solvent  substances  in  the 
soil.  Furthermore,  the  phosphate  of  the  animal  bone 
is  always  a  phosphate  of  lime,  which,  while  not 
soluble,  is  in  itself  more  readily  attacked  by  the 
natural  agencies  than  a  mineral  phosphate  which  has 
associated  with  the  bone  phosphate  other  minerals 
that  are  not  readily  attacked  by  those  agencies.  That 
is,  the  mineral  phosphates,  while  they  are  made  up 
chiefly  of  phosphate  of  lime,  are  associated  with  other 
minerals,  as  iron  and  alumina,  that  are  more  slowly 
attacked  than  the  phosphate  of  lime  itself,  and  to 
some  extent,  too,  prevent  the  full  effect  of  the  sol- 
vents, rather  than  encourage  their  action,  as  is  the 
case  with  bone. 

Influence   of  Fineness   of  Division 

In  the  second  place,  fineness  of  division  has  an 
important   bearing   upon   availability,    since    the    finer 


74  FERTILIZERS 

the  substance  is  ground,  the  greater  -will  be  the  sur- 
face area  exposed  to  the  natural  agencies  which  cause 
decay.  Thus  the  application  of  a  coarsely  ground 
phosphate  may  not  show  any  results  the  first  season, 
while  the  same  substance  ground  to  a  powder  may 
have  a  good  effect  the  first  season ;  that  is,  its  fine- 
ness permits  of  the  solubility  of  a  considerable  portion 
of   its  phosphoric  acid. 

The    Character   of  Soil   as   a   Factor   Influencing 
Availability 

In  the  third  place,  the  kind  of  soil  to  which  the 
phosphate  is  applied  may  influence  the  rate  at  which 
the  plants  may  obtain  it.  A  soil  which  is  open  and 
porous,  and  thus  permits  the  free  access  of  air  and 
circulation  of  water,  and  one  which  contains  a  large 
portion  of  other  matter  capable  of  decay,  vegetable  or 
animal,  presents  more  favorable  conditions  for  the 
solubility  of  phosphates  than  one  which  is  close  and 
compact  in  texture  and  purely  mineral  in  its  charac- 
ter, thus  preventing  the  free  access  of  air  and  water, 
and  in  which  no  organic  changes  are  taking  place. 
In  the  one  case  the  conditions  are  such  as  to  favor 
the  action  of  the  natural  agencies,  and  in  the  other 
they  are  such  as  to  retard  their  action. 

Influence   of  the   Kind   of   Crop 

In  the  fourth  place,  the  value  or  usefulness  of 
phosphates  is  measured  to  some  extent  by  the  charac- 


AVAILABTLITY    OF    PHOSPHATES  75 

teristics  of  the  plant  or  crop  to  which  they  are  ap- 
plied. Plants  differ  in  their  power  of  acquiring  food. 
Certain  plants  are  able,  because  of  their  peculiar  root 
system,  or  period  of  growth,  to  appropriate  food  more 
readily  from  insoluble  sources  than  others. 

General    Considerations 

All  these  considerations  must  be  observed  in 
determining  the  usefulness  of  a  phosphate.  It  is 
believed  by  experienced  farmers,  though  not  abso- 
lutely confirmed  by  experimental  inquiry,  that  animal 
bone,  for  example,  is  far  superior,  as  a  source  of 
phosphoric  acid,  for  most  crops,  to  the  mineral  phos- 
phates, though  both  may  be  ground  to  the  same 
degree  of  fineness ;  and  also,  that  the  finer  the 
bone  is  ground,  the  more  rapidly  will  it  give  up  its 
phosphoric  acid. 

Laboratory  tests  show  that  the  phosphoric  acid  in 
bone,  while  insoluble  in  water,  may  be  partly  dis- 
solved at  a  certain  temperature  by  a  neutral  solution 
of  ammonium  citrate.  This  medium  is  used  to  de- 
termine what  is  called  "available"  in  other  phos- 
phatic  products.  The  rate  of  solubility  in  this  medium 
is  measured  by  the  method  of  preparation  of  the  bone 
and  its  fineness,  the  phosphate  in  raw  bone  meal  of 
the  same  fineness  showing  rather  a  lower  rate  of 
solubility  than  the  phosphates  in  steamed  bone.  The 
phosphate  in  the  finest  steamed  bone  is  much  more 
soluble  than  that  in  the  coarser  grades.  This  measure 
of  the  rate  of   solubility  of   bone,  while   not,  perhaps, 


76  FERTILIZERS 

showing  the  exact  rate  at  which  the  plants  may 
obtain  it,  is  a  fairly  safe  guide  in  its  use  for  most 
crops,  as  compared  with  those  mineral  phosphates 
which  are  not  perceptibly  soluble  in  this  medium. 
The  range  of  solubility  of  different  kinds  and  grades 
of  bone  is  from  20  to  75  per  cent,  and  the  average 
of  a  large  number  show  about  30  per  cent  soluble 
in  citrate  of  ammonia,  which  would  be  called  "avail- 
able" if  found  in  mixed  fertilizers,  and  probably  can 
be  as  safely  depended  upon  as  the  available  shown 
in  other  products. 

In  any  case,  animal  bone,  or  finely  ground  mineral 
phosphates,  cannot  be  depended  upon  to  fully  meet  the 
needs  of  quick -growing  crops  for  phosphoric  acid,  but 
may  answer  an  excellent  purpose  where  the  object  is 
to  gradually  improve  the  soil  in  its  content  of  this 
constituent,  as  well  as  to  supply  such  crops  as  are 
continuous,  or  that  grow  through  long  periods,  as, 
for  example,  meadows,  pastures,  and  orchard  and 
vineyard   crops. 

As  to  the  specific  substance,  the  iron  phosphate, 
or  Thomas  phosphate  powder,  experiments  in  Europe 
have  shown  that  it  possesses  a  higher  rate  of  availa- 
bility than  other  phosphates  which  are  insoluble  in 
water,  but  which  show  the  same  rate  of  solubility 
in  ammonium  citrate,  though  its  solubility,  or 
availability,  is  measured  to  some  extent  by  the  degree 
of  fineness  to  which  it  is  ground;  and  it  is  believed 
that  its  special  form,  the  tetra- calcic,  also  exercises  a 
considerable  influence  upon  the  rate  of  availability. 

European   vegetation   and    field    experiments    show 


AVAILABILITY    OF    PHOSPHATES  77 

pretty  clearly  that  two  parts  of  phosphoric  acid  from 
the  Thomas  phosphate  powder  are  approximately 
equivalent  to  one  part  from  soluble  phosphoric  acid, 
and  that  this  phosphate  is  especially  useful  on  wet, 
marshy  soils  and  those  poor  in  lime.  Experiments 
conducted  in  this  country  practically  confirm  these 
conclusions. 

The  relative  availability  of  the  phosphates  in  the 
natural  guanos  has  also  been  shown  to  be  somewhat 
higher  than  in  other  insoluble  phosphates.  These 
latter  substances  for  this  reason  possess  a  distinct 
value  over  others  for  certain  classes  of  crops,  as,  for 
example,  cranberries,  where  the  soluble  phosphates 
would  be  liable  to  be  washed  out,  and  where  the 
organic  phosphates  would  be  liable  to  float  on  the 
surface  of  the  water,  and  also  where  lands  are  cold 
and  sour,  and  not  readily  fermentable. 

The  practical  point,  however,  to  the  farmer,  is  the 
amount  of  increase  that  he  may  obtain  from  a  certain 
definite  expenditure,  a  matter  which  will  be  discussed 
later,  in  the  discussion  of  the  use  of  fertilizers  for  the 
various  crops. 


CHAPTER  V 

SUPERPHOSPHATES— POTASH 

The  different  phosphates  mentioned  in  the  pre- 
vious chapter  constitute  the  sources  of  supply  for 
the  manufacture  of  commercial  fertilizers.  That  is, 
with  the  exception  of  animal  bone,  Thomas  phos- 
phate powder  and  natural  guanos,  they  are  used  more 
extensively  for  this  purpose  than  directly  on  the  land 
in  their  raw  state.  They  are  the  raw  materials  from 
which  the  manufactured  phosphatic  fertilizers  are  de- 
rived. The  purpose  of  the  manufacture  is  to  con- 
vert them  into  a  form  in  which  the  phosphoric  acid  is 
immediately  available,  and  thus  directly  useful  to  the 
plant.  The  term  "available"  in  this  case  is  used  in  the 
same  sense  as  in  the  discussion  of  the  forms  of  nitro- 
gen (Chap,  iii.),  and  it  means  that  when  the  phos- 
phoric acid  is  in  this  form,  the  plants  may  acquire  it 
immediately. 

INSOLUBLE    PHOSPHORIC    ACID 

Phosphate  of  lime  is,  chemically  speaking,  a  salt 
capable  of  existing  in  various  forms,  the  form  measur- 
ing in  large  degree  the  rate  of  availability.  The 
phosphate  of  lime,  as  it  exists  in  the  animal  bone  and 
mineral    phosphates,    for    example,    consists    of    three 

(78) 


FOBMS    OF   PHOSPHORIC  ACID  79 

parts  of  lime  and  one  of  phosphoric  acid.  This  is 
the  insoluble  form.  It  is  not  immediately  available, 
and  because  of  the  three  parts  of  lime  to  one  of 
phosphoric  acid,  which  it  contains,  it  is  also  called 
tricalcic,  tribasic,  or  bone  phosphate,  and  is  graph- 
ically expressed  in  the  accompanying  formula: 

Lime 

Lime  Phosphoric  Acid 

Lime 

That  is,  in  each  molecule,  however  small,  there  are 
three  parts  of  lime  and  one  part  of  phosphoric  acid. 

SOLUBLE    PHOSPHORIC    ACID 

In  another  form,  the  phosphate  consists  of  one  part 
of  lime  and  one  of  phosphoric  acid,  two  parts  of  the 
lime  in  the  tricalcic  form  being  replaced  with  water. 
This  form  is  called  monobasic,  or  monocalcic.  It  is 
a  saturated  phosphate.  There  could  be  no  less  than 
one  part  of  lime  to  one  of  phosphoric  acid,  and  such 
phosphates  are  called  acid  phosphates,  or  superphos- 
phates. The  combination  of  the  lime  and  phosphoric 
acid  may  be  shown  as  follows:     ' 

Lime 

Water  Phosphoric  Acid 

Water 

This  form  is  completely  soluble  in  water  and  im- 
mediately available,  and  when  applied  to  the  soil 
readily  distributes  itself  everywhere,  thus  making  it 
more  useful  than  any  other  form. 


80  FERTILIZERS 

REVERTED    PHOSPHORIC    ACID 

Another  form  of  phosphate  consists  of  two  parts 
of  lime  and  one  part  of  phosphoric  acid,  and  is  called 
dicaleic,  dibasic,  or  reverted.  One  part  of  the  lime 
in  the  insoluble  is  replaced  by  an  equivalent  of  water, 
and  is  expressed  as  follows: 

Lime 

Lime  Phosphoric  Acid 

Water 

The  reverted  form,  which  means  a  going  back  from 
the  soluble  toward  the  insoluble  form,  is  also  insoluble 
in  water,  but  is  readily  soluble  to  the  roots  of  plants. 

It  was  formerly  supposed  that  these  three  were 
the  only  forms  in  which  phosphoric  acid  existed,  but 
another  form,  in  which  four  parts  of  lime  are  com- 
bined with  one  of  phosphoric  acid,  and  thus  called 
tetrabasic,  or  tetracalcic,  has  been  found  quite  re- 
cently to  exist  in  the  Thomas  phosphate  powder: 

Lime 

Phosphoric  Acid 
Lime 

Lime 

This  form  is  insoluble  in  water,  though  it  has 
been  found  to  be  more  available  than  the  insoluble 
tribasic  form. 

HOW    SUPERPHOSPHATES    ARE    MADE 

Any  material  which  contains  a  high  content  of  the 
tricalcic  or  bone   phosphate,  60   per  cent    or   over,  is 


THE  MANUFACTURE  OF  SUPERPHOSPEATES      81 

suitable  for  the  manufacture  of  superphosphates,  pro- 
vided it  does  not  possess  a  too  high  content  of  dele- 
terious substances.  In  the  manufacture  of  superphos- 
phates, the  phosphate  is  first  ground  to  a  fine  powder, 
then  mixed  with  sulfuric  acid.  The  acid  dissolves  the 
phosphate,  and  two  parts  of  the  lime  which  are  com- 
bined with  the  phosphoric  acid  in  the  tricalcic  form 
are  first  set  free,  and  then  combined  with  the  sulfuric 
acid,  making  a  superphosphate  (monocalcic),  and  a 
sulfate  of  lime  or  gypsum.  That  is,  in  this  process, 
two  of  the  three  parts  of  the  lime  combined  with  the 
phosphoric  acid  to  form  the  insoluble  phosphoric 
acid,  are  removed,  thus  leaving  one  part  of  the  lime 
combined  with  the  phosphoric  acid,  making  the  super- 
phosphate. A  pure  superphosphate  is,  therefore,  a 
mixture  of  soluble  phosphate  and  of  sulfate  of  lime 
or  gypsum. 

The   Difference   in   the   Superphosphates  made 
from   the   Different   Materials 

In  the  early  use  of  superphosphates,  the  chief  raw 
material  was  animal  bone.  The  superiority  of  the 
bone  superphosphate,  or  dissolved  bone,  as  it  was 
called,  over  the  raw  bone,  was  manifest  at  once,  and 
the  familiarity  with  genuine  bone  superphosphates 
thus  early  acquired  by  farmers  was,  perhaps,  quite 
as  influential  as  any  other  in  creating  a  prejudice  in 
favor  of  their  continued  use  in  preference  to  super- 
phosphates derived  from  mineral  phosphates.  The 
opinion   that    the   bone   superphosphate   is  "the   best" 


B2  FEBTILIZEBS 

is  held  even  at  the  present  day,  notwithstanding  the 
equally  satisfactory  results  that  have  been  obtained 
from  the  use  of  the  superphosphates  from  other 
sources. 

Soluble   Phosphoric  Acid    Chemically   Identical, 
from    Whatever   Source   Derived 

Chemically  speaking,  the  soluble  phosphoric  acid 
produced  by  the  action  of  sulfuric  acid  upon  mineral 
phosphates  is  identical  with  the  soluble  phosphoric 
acid  derived  from  animal  bone,  and  if  the  soluble 
from  each  could  be  separated  from  the  other  sub- 
stances with  which  they  are  associated,  there  would 
be  no  difference  whatever  in  the  results  of  their  use. 
They  are  identical ;  just  as  much  so  as  ammonia 
obtained  in  the  manufacture  of  bone-black  from 
bones  is  identical  with  the  ammonia  obtained  in  the 
manufacture  of  illuminating  gas  or  coke.  In  many 
cases,  doubtless,  superior  results  have  been  obtained 
from  the  use  of  the  animal  bone  superphosphate, 
though  this  has  not  been  due  to  any  inferiority  of  the 
available  phosphoric  acid  in  the  mineral  superphos- 
phate, but  rather  to  the  fact  that  substances  have 
been  compared  that  are  not  strictly  comparable.  They 
are  radically  different.  The  one  contains,  in  addition 
to  its  available  phosphoric  acid,  the  only  fertilizing 
ingredient  in  the  mineral  superphosphate,  considerable 
nitrogen,  and,  moreover,  it  contains  its  insoluble  phos- 
phoric acid  in  a  form  that  is  liable  to  decay  more 
rapidly  than    the  insoluble  in  the  mineral   phosphate. 


PEOSPEATES    AND   SUPUBPEOSPEATES  83 

Soluble  phosphoric  acid  is  a  definite  compound.  The 
source  from  which  it  is  derived  does  not  influence 
this  point,  and  the  action  of  a  definite  quantity  is 
also  identical  when  conditions  are  similar. 

PHOSPHATES     AND     SUPERPHOSPHATES     ARE     NOT 
IDENTICAL 

The  idea  in  the  term  "phosphate"  should  also  be 
kept  distinct  from  that  conveyed  by  the  term  "super- 
phosphate." The  first  means,  and  should  be  applied 
to,  any  material  containing  as  its  chief  constituent 
phosphoric  acid;  the  other  means,  and  should  be  ap- 
plied to,  any  material  containing  soluble  phosphoric 
acid  as  its  chief  constituent.  The  phosphates  which 
have  already  been  described  are  each  capable  of  being 
converted  into  a  superphosphate,  as  animal  bone  super- 
phosphate, South  Carolina  rock  superphosphate,  bone- 
black  superphosphate,  bone-ash  superphosphate,  Florida 
rock  superphosphate,  and  Tennessee  rock  superphos- 
phate. These  superphosphates  vary  in  their  content 
of  soluble  phosphoric  acid,  due  both  to  the  variation 
in  the  content  of  the  phosphoric  acid  in  the  phosphates 
used  as  raw  materials,  and  to  the  excellence  of  the 
method  of  manufacture.  In  other  words,  the  super- 
phosphates, while  practically  identical  in  so  far  as  the 
form  of  phosphoric  acid  is  concerned,  vary  in  their 
total  content  of  soluble  phosphoric  acid.  For  ex- 
ample, superphosphates  made  from  the  animal  phos- 
phates, as  bone-black,  bone -ash,  etc.,  are  usually 
richer    in    soluble    phosphoric   acid    than    those   made 


84  FERTILIZERS 

from  animal  bone,  or  from  many  of  the  mineral 
phosphates,  because  these  phosphates  are  of  such  a 
character  as  to  enable  the  manufacturer  to  convert  all 
the  phosphoric  acid  present  into  a  soluble  form,  and 
at  the  same  time  to  secure  a  fine,  dry  product,  that 
may  be  readily  handled  —  an  important  consideration 
in  making  superphosphates. 

"Mineral  phosphates,  both  because  of  their  hard- 
ness and  of  the  presence  of  other  minerals,  which  are 
attacked  by  the  acid,  are  less  easily  dissolved,  and 
require  more  acid  in  proportion  to  the  phosphate 
present  than  those  from  organic  sources.  They  are 
also  less  absorbent,  preventing  the  acid  from  perme- 
ating the  mass  of  the  material,  and  hence  it  is  more 
difiicult  to  secure  good  condition  when  sufficient  acid 
is  used  to  dissolve  the  phosphate.  In  making  super- 
phosphates from  these  materials,  less  acid  is  used  than 
is  required  to  completely  dissolve  the  phosphates,  and 
there  is,  therefore,  always  present  in  them  more  or 
less  of  the  insoluble  phosphoric  acid. 

"In  the  case  of  animal  bone,  too,  less  sulfuric  acid 
is  used  than  is  required  to  completely  dissolve  the 
phosphoric  acid.  Otherwise,  a  gummy,  sticky  product 
would  result,  due  largely  to  the  organic  matter  in  the 
bone.  The  insoluble  phosphoric  acid  in  bone,  bone- 
black,  and  bone -ash  superphosphates  is,  however,  of 
greater  value  than  the  insoluble  in  the  mineral  phos- 
phates, for  reasons  already  given. 

"In  superphosphates,  too,  there  is  nearly  always 
present  a  greater  or  less  amount — depending  upon  the 
material — of  the  second  form  of    phosphoric  acid,  the 


PHOSPHATES   AND    SUPERPHOSPHATES  85 

diealcic,  reverted  or  retrograde.  This  form  usually 
exists  in  the  greatest  amounts  in  those  made  from 
mineral  phosphates,  which  is  believed  to  be  due  either 
to  the  soluble  acting  upon  the  insoluble  portions,  or 
to  the  presence  of  oxide  of  iron  and  alumina,  which 
combine  with  a  portion  of  the  soluble  phosphoric  acid. 
The  soluble  goes  back  to  the  less  soluble  diealcic 
form."* 

Aikman  states  the  matter  very  clearly  in  the  fol- 
lowing words :t  "A  change  which  is  apt  to  take  place 
in  superphosphate  after  its  manufacture  is  what  is 
known  as  'reversion  of  the  soluble  phosphate.'  Thus 
it  is  found  that  on  keeping  superphosphate  for  a 
long  time  the  percentage  of  soluble  phosphate  becomes 
less  than  it  was  at  first.  The  rate  at  which  this 
deterioration  of  the  superphosphate  goes  on  varies  in 
different  samples.  In  a  well-made  article,  it  is  prac- 
tically inappreciable,  whereas  in  some  superphosphates, 
made  from  unsuitable  materials,  it  may  form  a  con- 
siderable percentage.  The  causes  of  this  reversion 
are  two-fold.  For  one  thing,  the  presence  of  unde- 
composed  phosphate  of  lime  may  cause  it.  This 
source  of  reversion,  however,  is  very  much  less  im- 
portant than  the  other,  which  is  the  presence  of  iron 
and  alumina  in  the  raw  material.  When  a  soluble 
phosphate  reverts,  what  takes  place  is  the  conversion 
of  the  monocalcic  phosphate  into  the  diealcic. 

"  Where  reversion  is  due  to  the  presence  of  iron  and 


*" First  Principles  of  Agriculture."    Silver,  Burdett  &  Co.,  Boston. 

t"  Manures  and  Manuring."    An  excellent  English  work,  of  recent  issue. 


86  FERTILIZERS 

alumina  in  the  raw  material,  the  nature  of  the  reac- 
tion is  not  well  understood,  and  is,  consequently,  not 
so  easily  demonstrated  as  in  the  former  case.  Where 
iron  is  present  in  the  form  of  pyrites,  or  ferrous 
silicate,  it  does  not  seem  to  cause  reversion.  It  is 
only  when  it  is  present  in  the  form  of  oxide  (and  in 
most  raw  phosphatic  materials  it  is  generally  in  this 
form)  that  it  causes  reversion  in  the  phosphate." 

Aikman  also  discusses  the  value  of  reverted  phos- 
phates, showing  the  estimation  in  which  they  are 
held  in  England:  "The  value  of  reverted  phosphate 
is  a  subject  which  has  given  rise  to  much  dispute 
among  chemists.  That  it  has  a  higher  value  than  the 
ordinary  insoluble  phosphate  is  now  admitted,  but  in 
this  country,  in  the  manure  trade,  this  is  not  as  yet 
recognized.  At  first  it  was  thought  that  it  was  im- 
possible to  estimate  its  quantity  by  chemical  analysis. 
This  difficulty,  however,  has  been  overcome,  and  it  is 
generally  admitted  that  the  ammonium  citrate  process 
furnishes  an  accurate  means  of  determining  its  amount. 
Both  on  the  continent  and  in  the  United  States 
reverted  phosphate  is  recognized  as  possessing  a 
monetary  value  in  excess  of  that  possessed  by  the 
ordinary  insoluble  phosphates.  The  result  is,  that 
raw  mineral  phosphates  containing  iron  and  alumina 
to  any  appreciable  extent  are  not  used  in  this  country, 
although  they  do  find  a  limited  application  in  America 
and  on  the  continent," 

As  stated  by  Aikman,  the  reverted  phosphoric  acid 
due  to  the  presence  of  undecompoged  phosphate,  as 
well  as  the  reverted   due  to  the  presence  of  iron  and 


DOUBLE    SUPEBPHOSPHATES  87 

alumina,  are  recognized  by  the  chemists  in  this  coun- 
try, and  this  recognition  is  strongly  encouraged  by 
commercial  interests,  because  of  the  fact  that  our 
mineral  phosphates  contain,  as  a  rule,  iron  and 
alumina,  which  by  their  action  reduce  the  percentage 
of  the  soluble.  The  method  of  chemical  analysis 
which  has  been  adopted  by  the  American  Association 
of  Official  Agricultural  Chemists  recognizes  this  form, 
and  it  is,  therefore,  determined  and  included  in  the 
"total  available"  in  statements  of  analysis.  In  one 
state,  New  Jersey,  the  law  requires  that  the  dicalcic 
form  only  shall  be  recognized,  and  it  assumes  that  the 
agricultural  value  of  this  form  is  equal  to  that  of  the 
soluble. 

DOUBLE    SUPERPHOSPHATES 

In  addition  to  the  superphosphates  made  directly 
from  the  various  materials  mentioned,  a  special  sub- 
stance, called  a  "double  superphosphate,"  which  may 
be  made  by  dissolving  low-grade  phosphates  with  an 
excess  of  dilute  sulfuric  acid,  or  those  too  poor  in 
phosphoric  acid  to  make  a  high-grade  superphosphate. 
The  dissolved  phosphoric  acid  thus  obtained,  together 
with  the  excess  of  sulfuric  acid,  are  separated  from 
the  insoluble  materials  by  filtering,  which  acids,  after 
concentration,  are  then  used  for  dissolving  the  better 
phosphates  ;  and  because  the  acids  used  for  dissolving 
the  phosphates  contain  phosphoric  acid,  the  content 
of  available  phosphoric  acid  in  these  products  is 
more    than    double    that    contained    in    the    ordinary 


88  FERTILIZERS 

products.  These  are  mostly  manufactured  in  Europe, 
and  are  not  used  to  any  extent  in  this  country.  They 
possess  the  advantage  of  containing  a  minimum  of 
impurities  and  a  maximum  of  phosphoric  acid  in  a 
soluble  form. 

In  stating  the  composition  of  superphosphates,  the 
three  forms  of  phosphoric  acid  are  all  recognized. 
The  sum  of  the  soluble  and  reverted  forms  is  called 
the  "total  available,"  because  these,  as  already  stated, 
are  regarded  as  immediately  useful  to  the  plant.  In 
commercial  transactions  in  mineral  superphosphates, 
the  total  available  only  is  regarded, —  the  content  of 
insoluble  being   ignored. 

'  CHEMICAL    COMPOSITION    OF    SUPERPHOSPHATES 

As  already  stated,  the  composition  of  the  super- 
phosphates varies  according  to  the  richness  in  phos- 
phoric acid  of  the  phosphates  used,  and  according 
to  the  character  of  the  material.  Bone -ash  and  bone- 
black  superphosphates  are  more  uniform  in  composi- 
tion than  those  derived  from  the  mineral  phosphates, 
and  the  phosphoric  acid  is  practically  all  in  the  solu- 
ble form.  They  contain  on  the  average  about  16  per 
cent  of  total  available  phosphoric  acid.  The  mineral 
or  rock  superphosphates  differ  from  these  in  being 
more  variable  in  their  total  content  of  available,  and 
in  showing  wider  variations  in  the  proportions  of 
reverted,  the  latter  depending  upon  the  skill  in  manu- 
facture, as  well  as  the  character  of  the  original 
material.    Well  made  South  Carolina  rock  superphos- 


COMPOSITION    OF   SUPERPHOSPHATES  89 

phates  contain  from  12  to  14  per  cent  of  total  availa- 
ble, of  which  1  to  3  per  cent  is  dicalcic,  or  reverted. 
There  are  several  grades  of  the  Florida  rock  super- 
phosphates, due  to  the  variation  in  the  composition  of 
the  various  raw  phosphates.  The  pebble  superphos- 
phates are  the  richest,  often  containing  as  high  as  16 
or  17  per  cent  of  total  available,  with  varying  percent- 
ages of  reverted  and  insoluble.  The  Tennessee  super- 
phosphates also  vary  from  the  same  cause,  the  richest 
showing  as  high  as  16  to  18  per  cent  of  total  availa- 
ble. The  concentrated,  or  double  superphosphates,  may 
contain  as  high  as  45  per  cent  of  available,  practically 
all  of  which  is  soluble.  The  superphosphates  made 
from  animal  bone  are  usually  more  variable  in  their 
composition  than  those  made  from  bone-black,  bone- 
ash  or  mineral  phosphates,  and  the  variation  is  due 
both  to  the  variability  of  the  raw  materials  and  the 
difficulties  involved  in  their  change  into  superphos- 
phates. The  usual  guarantee  on  an  animal  bone 
superphosphate  is  12  per  cent  available,  and  from  3  to 
5  per  cent  of  insoluble.  These  superphosphates  also 
differ  from  the  mineral  superphosphates  in  containing 
nitrogen  in  addition  to  their  phosphoric  acid.  They 
are,  therefore,   really   ammoniated  superphosphates. 

Well  Made  Superphosphates  Contain  no  Free  Add 

In  the  earlier  history  of  the  use  of  acid  phosphates, 
or  rock  superphosphates,  objections  were  urged  against 
them,  and  are  to  some  extent  at  the  present  time, 
because    of    the    supposed    deleterious    effects    of    the 


90  FERTILIZERS 

acids  contained  in  them,  and  these  objections  were 
undoubtedly  encouraged, — certainly  not  discouraged, — 
by  those  manufacturers  who  used  only  genuine  bone 
superphosphates.  While  the  objections  on  this  ground 
may  have  had  some  basis  in  earlier  times,  before  their 
manufacture  was  well  understood,  there  can  be  no 
rational  objection  to  their  use  at  the  present  time, 
when  they  are  properly  made;  for  while  in  fresh  super- 
phosphates a  portion  of  the  phosphoric  acid  may  be  in 
the  form  of  "free"  phosphoric  acid,  this  form  in  ordi- 
nary superphosphates  is  practically  all  combined  with 
lime  or  other  minerals  before  it  is  placed  upon  the 
market,  and  there  is  really  no  more  "free"  acid  in 
the  rock  superphosphate  than  in  any  other.  It  is  quite 
likely  this  erroneous  impression  arose  from  the  fact 
that  strong  sulfuric  acid  was  used  in  the  manufacture, 
and  the  belief  existed  that  it  remained  as  such.  No 
free  sulfuric  acid  exists  in  well  made  superphosphates. 
The  sulfuric  acid  is  combined  with  the  lime  to  form 
gypsum,  as  already  described,  and  the  free  phosphoric 
acid  combines  with  the  lime  to  form  either  a  soluble 
or  a  reverted  form. 

Phosphoric  Acid  Remains  in   the   Soil    Until   Taken 
Out  by   Plants 

The  phosphoric  acid  in  superphosphates,  though 
soluble  in  water,  is  not  readily  washed  from  the  soil. 
The  real  object  of  making  it  soluble  is  to  enable  its 
better  distribution.  If  it  were  possible  to  as  cheaply 
prepare  the  dicalcic  or  reverted  form  as  the  soluble,  it 


THE    FlXATIOIf    OF   PHOSPHORIC    AC  IB  91 

would,  perhaps,  be  quite  as  useful  from  the  standpoint 
of  availability.  After  the  soluble  is  distributed  in  the 
soil,  it  is  fixed  there  by  combining  with  the  lime  and 
other  minerals  present.  It  is  believed  that  it  assumes, 
first,  by  the  larger  relative  proportion  of  lime  usually 
present  in  soils,  the .  dicalcic  form,  though  it  is  not 
positively  certain  that  in  the  presence  of  an  abundance 
of  lime,  or  that  in  time,  it  may  not  assume  the  in- 
soluble tricalcie  form.  The  soluble  phosphoric  acid 
may  also  combine  with  the  iron  and  alumina  in  the 
soil,  and  form  phosphates  of  these  elements,  though 
recent  investigations  lead  to  the  conclusion  that  these 
conditions  are  much  more  rare  than  was  at  one  time 
supposed.  The  time  required  for  the  fixing  of  the 
phosphoric  acid,  as  well  as  the  form  it  may  eventually 
assume,  depends  chiefly  upon  the  character  and  com- 
position of  the  soil.  In  those  rich  in  lime,  the  fixa- 
tion is  most  rapid,  though  in  no  sense  is  the  fixation 
immediate,  and  in  such  soils  the  fixation  is  probably 
largely  completed  in  the  course  of  a  week.  On  clay 
soils,  containing  a  low  percentage  of  lime,  and  in 
light  soils  that  contain  little  clay  or  organic  matter, 
the  fixation  is  much  slower,  though  even  in  these  the 
chances  are  that  no  serious  loss  of  phosphoric  acid 
occurs.  Seldom  do  we  find  more  than  traces  of  phos- 
phoric acid  in  drainage  waters,  even  when  heavy 
applications  of  soluble  phosphoric  acid  are  followed 
by  heavy  rains.  The  fact  that  the  fixing  power  of 
soils  practically  prevents  the  loss  of  phosphoric  acid 
should,  however,  not  be  used  as  an  argument  in  favor 
of  the  careless  use  of  superphosphates. 


92  FERTILIZERS 


POTASH    SALTS 


Until  the  discovery  of  the  mines  of  crude  potash 
salts  in  Stassfurt,  Germany,  in  1859,  and  which  have 
been  worked  since  1862,  the  chief  source  of  potash 
for  farm  plants,  other  than  that  contained  in  yard 
manures,  was  wood  ashes.  The  supply  from  this 
source  now,  however,  is  sufficient  to  meet  all  imme- 
diate as  well  as  future  demands,  since  the  deposits 
are  practically  inexhaustible,  though  notwithstanding 
the  abundance  of  the  supply  and  the  improvements 
made  in  the  methods  of  utilizing  the  various  salts, 
other  than  potash,  contained  in  the  deposits,  it  is  the 
only  fertilizer  constituent  which  has  remained  prac- 
tically constant  in  price  during  the  past  fifteen  years. 
In  this  period  not  only  have  wide  fluctuations  occurred 
in  prices  of  nitrogen  and  phosphoric  acid  from  the 
different  sources,  but  they  are  much  lower  now  than 
formerly. 

The  Importance   of  Potash   as   a    Constituent  of 

Fertilizers 

It  has  been  attested  that  potash  is  of  relatively  less 
importance  than  either  nitrogen  or  phosphoric  acid, 
inasmuch  as  good  soils  are  naturally  richer  in  this 
element,  and  because  a  less  amount  is  removed  in 
general  farming  than  of  either  nitrogen  or  phosphoric 
acid,  as  the  potash  is  located  to  a  less  extent  in  the 
grain  than  in  the  straw,  which  is  retained  upon  the 
farm.    It  is,  however,  a  very  necessary  constituent  of 


FORMS    OF    POTASE  93 

fertilizers,  being  absolutely  essential  for  those  intended 
for  light,  sandy  soils  and  for  peaty  meadow  lands,  as 
well  as  for  certain  potash -consuming  crops,  as  potatoes, 
tobacco  and  roots,  since  these  soils  are  very  deficient 
in  this  element,  and  the  plants  mentioned  require  it  in 
larger  proportion  than  do  others.  In  fact,  it  is  be- 
lieved by  many  careful  observers, — and  the  belief  has 
been  substantiated  in  large  part  by  experiments  already 
conducted, — that  the  average  commercial  fertilizer  does 
not  contain  a  sufficient  amount  of  this  element.  It  is 
a  particularly  useful  constituent  element  in  the  building 
up  of  worn-out  soils,  because  contributing  materially 
to  the  growth  of  the  nitrogen -gathering  legumes,  an 
important  crop  for  this  particular  purpose. 

Forms   of  Potash 

Potash,  as  has  already  been  stated  in  the  discussion 
of  phosphoric  acid  and  nitrogen,  exists  in  various 
forms,  but  it  differs  from  the  other  elements  in  that 
its  chemical  form  or  combination  seems  to  exert  but 
relatively  little  influence  upon  the  availability  of  the 
constituent.  For  example,  it  may  be  in  the  form  of 
a  muriate  or  chlorid,  of  a  sulfate  or  of  a  carbonate, 
and  while  there  is  a  difference  in  the  diffusibility  of 
these  different  compounds, — that  is,  a  difference  in  the 
rate  at  which  they  will  distribute  in  the  soil  before 
becoming  fixed, — there  seems  to  be  very  little  dif- 
ference in  the  rate  of  the  absorption  of  the  potash 
by  the  plant.  Nevertheless,  the  form  of  potash  must 
be  observed,  because  of  the  possible  influence  that  the 


194  FEBTILIZEBS     _ 

substances  with"  which  it  combines  may  exert  in 
reducing  the  marketable  quality  of  the  crop  to  which 
it  is  applied.  This  influence  has  been  very  distinctly 
observed,  particularly  in  the  growing  of  tobacco,  sugar- 
beets  and  potatoes,  and  it  has  been  shown  that  the 
potash  in  the  form  of  a  chlorid  (or  muriate)  does  exert 
a  very  deleterious  effect,  especially  on  tobacco.  In  fact, 
tobacco  manures  should  not  contain  potash  in  the 
form  of  a  muriate.  For  such  crops  as  the  various 
clovers,  Indian  corn  (maize),  and  the  various  grasses,  no 
particular  difference  has  been  observed,  and  the  form 
of  potash  that  may  be  procured  at  the  lowest  price 
per  pound  of  the  constituent  is  the  one,  other  things 
being  equal,  to  use  for  these  crops. 

Kainit 

In  the  next  place,  the  potash  salts  that  may  be 
obtained  are  divided  into  two  classes  ;  first,  the  crude 
products  of  the  mines,  and  second,  the  manufactured 
products.  Of  the  crude  products,  kainit  is  the  one 
more  largely  used  in  this  country  than  any  other. 
The  potash  contained  in  it  is  practically  all  in  the 
form  of  a  sulfate,  though  its  effect  is  the  same  as  if 
it  were  in  the  form  of  a  muriate,  because  of  the  large 
quantities  of  other  salts,  chiefly  sodium  chlorid,  or 
ordinary  salt,  and  magnesium  chlorid,  with  which  the 
sulfate  of  potash  is  associated.  It  contains  on  the 
average  12.5  per  cent  of  actual  potash,  or  equivalent 
to  about  23  per  cent  of  sulfate  of  potash  and  33  per 
cent   of    ordinary    salt,    and    smaller    percentages    of 


CRUDE    POTASH   SALTS  95 

magnesium  chlorid  and  magnesium  sulfate.  Because 
of  its  low  content  of  potash  as  compared  with  the 
manufactured  products,  the  cost  of  the  actual  potash 
is  usually  greater  than  in  these,  owing  to  the  in- 
creased cost  of  shipping  and  handling  per  unit  of 
potash.  It  is  more  generally  used  near  the  sources 
of  supply,  rather  than  at  a  distance,  unless  the  sub- 
stances, as  ordinary  salt,  also  exert  a  beneficial  indirect 
influence  upon  the  soil,  as  is  very  frequently  the 
case.  It  is  not  advisable  to  apply  it  immediately 
preceding  the  planting,  nor  in  the  hill  or  row,  because 
of  the  danger  to  the  young  plant  from  the  excess  of 
both  the  chlorids  of  sodium  and  magnesium,  which 
are  injurious  to  the  tender  rootlets.  Where  its  use  is 
intended  to  benefit  the  immediate  crop,  it  should  be 
applied  a  considerable  time  before  the  crop  is  planted, 
in  order  that  it  maj'  be  well  distributed,  and  that  a 
portion  of  the  chlorids,  which  are  extremely  soluble, 
may  be  washed  into  the  lower  layers,  or  into  the 
drains. 

Sylvinit 

Sylvinit  is  somewhat  similar  to  kainit  in  composi- 
tion, in  that  it  does  not  contain  a  large  amount  of 
actual  potash,  and  the  potash  is  associated  with  other 
substances,  as  sodium  and  magnesium  chlorids,  though 
less  than  is  the  case  with  kainit.  The  potash  in  the 
sylvinit,  however,  exists  both  in  the  form  of  a  sulfate 
and  of  a  chlorid.  It  is  not  as  largely  exported  to 
this  country  as  the  kainit,  and  contains  on  the  average 


96  FERTILIZERS 

about  16  per  cent  of  actual  potash.  Its  effect  as  an 
indirect  manure  is  very  similar  to  that  of  kainit, 
the  salts  associated  with  the  potash  having  a  beneficent 
effect  in  dissolving  and  making  other  substances  in 
the  soil  available  to  the  plant,  particularly  phosphates, 
as  well  as  aiding  in  the  improvement  of  the  physical 
character  of  soils. 

Muriate   of  Potash 

Of  the  manufactured  products,  the  muriate  (chlorid) 
of  potash  is  more  generally  used  than  any  of  the 
others.  It  varies  somewhat  in  composition,  accord- 
ing to  the  method  of  manufacture,  though  prac- 
tically only  three  grades  are  offered.  That  most 
commonly  met  with  in  this  country  contains  about 
50  per  cent  of  actual  potash,  equivalent  to  80  per 
cent  muriate.  The  chief  impurities  are  common  salt, 
or  sodium  chlorid,  and  insoluble  matter,  which  are  not 
deleterious  substances.  The  lower  the  content  of 
potash  the  higher  the  content  of  impurities,  though 
in  all  cases  this  form  of  potash  is  sold  upon  the  basis 
of  80  per  cent  muriate. 

Recently  a  Scotch  kiln -dried  muriate  of  potash  has 
been  offered,  which  is  much  richer  in  actual  potash 
than  the  other  grades,  containing  over  98  per  cent  of 
pure  muriate.  The  chief  advantage  of  this  higher 
grade  is  that  the  cost  of  handling  per  unit  of  actual 
potash  is  reduced,  a  point  of  considerable  importance 
at  points  distant  from  sources  of  supply.  The  actual 
potash  is  no  better  than  in  the  lower  grades. 


HIGE-GBADE   POTASH    SALTS  97 

High-grade   Sulfate  of  Potash 

High-gi'ade  sulfate  of  potash  is  usually  sold  on  a 
purity  basis  of  98  per  cent,  or  an  equivalent  of  53  per 
cent  actual  potash.  It  naturally  varies  somewhat  in 
its  composition,  owing  to  possible  impurities,  either 
introduced  or  imperfectly  removed.  It  is,  however, 
regarded  as  preferable  to  the  muriate  for  some  crops, 
for  the  reasons  already  given  (page  94),  though  until 
recent  years  it  has  been  much  more  expensive,  and 
thus  not  so  largely  used  by  the  manufacturers  of 
fertilizers.  It  is  rather  less  diffusible  than  the  muri- 
ate, though  it  is  not  believed  to  be  inferior  to  it  as  a 
source  of  actual   potash. 

Double   Sulfate   of  Potash  and  Magnesia 

This  is  a  lower  grade  in  its  content  of  potash, 
though  similar  to  the  high  grade  in  its  effect,  as  it 
contains  no  deleterious  substances,  and  in  many  cases 
the  sulfate  of  magnesia  with  which  it  is  associated  is 
believed  to  be  of  considerable  service.  The  potash 
contained  in  it  is  equivalent  to  about  26  per  cent  of 
actual  potash,  though  lower  grades  are  made.  These 
are  known  under  the  name  of  double -manure  salts. 
The  cost  of  the  actual  potash  in  the  double  sulfate  is 
also  greater  than  in  the  muriate. 

Upon  standing,  all  of  the  potash  salts  have  a  ten- 
dency to  become  hard,  though,  with  the  exception  of 
kainit,  they  are  easily  pulverized,  and  thus  readily 
distributed,  either  broadcast  or  in  drills. 


98  FERTILIZERS 

Fixation  of  Potash 

Potash,  like  phosphoric  acid,  is  readily  fixed  in  the 
soil,  though  the  chlorids  with  which  it  is  combined 
when  applied  may  form  soluble  compounds  that  are 
readily  leached  from  the  soil.  For  example,  the 
chlorin  combined  with  the  muriate  may  be  combined 
with  lime  or  soda,  forming  soluble  chlorids  of  lime  or 
soda ;  hence,  heavy  applications  of  muriate  of  potash 
may  result  in  the  exhaustion  of  lime  in  the  soil.  The 
fact  that  the  potash  is  fixed,  and  that  the  chlorids 
remain  soluble,  enables  the  application  of  a  large 
quantity,  which  might  otherwise  be  injurious.  That 
is,  if  muriate  of  potash  is  applied  a  considerable 
time  before  the  crop  that  may  be  injured  by  excess 
of  chlorids  is  planted,  the  chlorids  are  washed  out, 
while  the  potash  remains. 

Another  point  of  importance  should  be  observed  in 
this  connection :  the  rapidity  of  fixation  on  manj'^  soils, 
especially  those  of  an  alluvial  character,  which  ex 
plains  the  recommendations  frequently  made  to  apply 
potash  salts  broadcast  and  immediately  cultivate  in, 
otherwise  the  fixation  would  take  place  at  points  of 
contact,  and   the  distribution  be  incomplete. 


CHAPTER  VI 

MISCELLANEOUS  FERTILIZING  MATERIALS 

In  addition  to  the  specific  fertilizer  materials  de- 
scribed in  the  previous  chapters,  which  constitute  the 
standard  sources  of  supply,  a  number  of  other  pro- 
ducts exist,  and  should  be  considered  here.  Certain 
of  these  may  serve  in  the  manufacture  of  fertilizers, 
and  certain  others,  which  are  not  suitable  for  this  pur- 
pose, may  be  used  to  advantage  either  because  they 
furnish  the  constituents  in  considerable  quantities,  or 
in  other  ways  assist  in  improving  the  fertility  of  the 
soil.  They  are  often  a  cheap  source  of  nitrogen, 
phosphoric  acid  or  potash,  besides  contributing  toward 
"condition"  of  soil,  which  exercises  a  decided  influ- 
ence in  making  possible  the  best  use  of  commercial 
fertilizers. 

Furthermore,  while  a  consideration  of  these  products 
may  not  be  regarded  as  strictly  pertaining  to  the  sub- 
ject of  commercial  fertilizers,  a  discussion  of  them  is 
valuable,  in  order  that  certain  impressions  now  existing 
concerning  them  may  be  corrected.  These  impressions, 
while  not  entirely  erroneous,  are  not  wholly  in  accord 
with  scientific  facts,  particularly  as  to  how  far  they 
may  substitute  the  better  products;  and  on  this  point 
information  as  full  and  exact  should  be  had  as  the 
limited  knowledge   that  we   have  of  the   subject   will 

(99), 


100  FEBTILIZEBS 

permit.  These  various  products  cannot  be  strictly 
classified  into  the  three  main  groups :  nitrogenous, 
phosphatic  and  potassic.  They  are,  as  a  rule,  rather 
general  in  their  effect ;  they  contain  small  amounts 
of  all  the  essential  constituents  rather  than  large 
amounts  of  one  or  two,  and  many  of  them  are  useful, 
practically  altogether  because  of  their  indirect  action. 

TOBACCO  STEMS  AND  STALKS 

Tobacco  stems  consist  of  the  waste  stems  or  ribs 
of  the  leaves,  and  parts  of  the  leaves  themselves, 
which  result  from  the  stripping  of  tobacco  for  the 
manufacture  of  cigars,  or  for  smoking  and  chewing 
tobacco.  The  stalks  include  the  main  stem  and 
branches  of  the  plant.  The  stems  are  frequently 
ground  and  sold  as  a  fertilizer,  and  the  product  is 
chiefly  valuable  for  its  nitrogen  and  potash  —  the 
nitrogen  ranging  in  content  from  2  to  3  per  cent 
and  the  potash  from  6  to  10  per  cent.  They  contain 
but  small  amounts  of  phosphoric  acid.  The  nitrogen 
exists  in  both  the  nitrate  and  organic  forms.  The 
nitrate  form  constitutes  from  one -third  to  one- 
half  of  the  total  nitrogen,  and  its  presence  is  due 
both  to  the  fact  that  nitrogen  exists  as  such  in  the 
tobacco  plant,  and  to  the  fact  that  saltpetre  (nitrate 
of  potash)  is  frequently  added  in  order  to  improve 
the    marketable     quality    of     the     lower    grades    of 


Note. —  Full  discussions  of  stable  manures  are  contained  in  Roberts' 
"Fertility  of  the  Land;"  and  that  book  also  has  a  table  of  compositions 
of  very  many  materials  which  are  used  .for  fertilizing  the  land. 


TOBACCO    STEMS  101 

tobacco.  The  potash  occurs  largely  in  the  soluble 
form,  and  is  free  from  chlorids.  The  tobacco  stalks 
are  somewhat  richer  in  nitrogen  than  the  stems, 
ranging  from  3  to  4  per  cent,  and  are  poorer  in  pot- 
ash— about  4  to  5  per  cent  of  potash — though  the 
forms  of  these  two  constituents  are  similar  in  the 
case  of  both  to  those  contained  in  the  stems.  Both 
stems  and  stalks  may  be  frequently  obtained  in  the 
vicinity  of  towns  where  tobacco  manufacture  is  carried 
on,  and  while  more  variable  in  their  content  of  nitro- 
gen and  potash  than  the  ground  stems  and  stalks, 
due  largely  to  the  variations  in  the  content  of  mois- 
ture, they  are  a  useful  and  often  a  very  cheap  source 
of  nitrogen  and  "potash. 

These  waste  tobacco  products  are  free  from  dele- 
terious compounds,  and  for  this  reason  alone  are 
highly  valued  as  a  fertilizer  for  tobacco,  as  well  as 
for  small  fruits,  for  which  they  are  especially  useful, 
because  of  their  known  insecticidal  value.  A  ton  of 
tobacco  stems  of  good  quality  contains  nitrogen  equiv- 
alent to  the  amount  contained  in  500  pounds  of  ni- 
trate of  soda,  and  potash  equivalent  to  the  amount 
contained  in  200  pounds  of  high-grade  sulfate  of 
potash.  They,  therefore,  possess  a  distinct  value  as 
a  source  of  these  constituents. 

CRUDE     FISH    SCRAP 

It  frequently  happens  that  farmers  are  so  situated 
as  to  be  able  to  procure  directly  from  the  fishermen 
the  fish  scrap  from  which   dried  ground  fish  is  made. 


102  FERTILIZERS 

Very  large  amounts  are  used  in  this  crude  form  in 
our  coast  states,  particularly  New  England  and  the 
middle  states.  This  material,  while  chiefly  valuable 
for  its  nitrogen,  is  not  uniform  in  its  content  of  fer- 
tilizing constituents,  owing  to  the  wide  variation  in 
the  content  of  moisture,  or  water,  which  may  range 
from  as  low  as  25  to  as  high  as  75  per  cent.  The 
nitrogen,  of  course,  varies  with  the  dry  matter,  and 
ranges  from  2.5  to  8  per  cent.  The  scrap  also  con- 
tains considerable  amounts  of  phosphoric  acid,  ranging 
from  2  to  6  per  cent.  The  fish  scrap  in  this  form, 
too,  is  less  valuable  as  a  source  of  nitrogen  than  the 
dried  ground  material,  because  of  its  coarser  condi- 
tion, requiring  a  longer  time  for  decay. 

The  whole  fishes  (menhaden)  are  also  used  either 
directly  or  in  a  composted  form  in  many  instances, 
and  the  excellent  results  obtained  are  mainly  due  to 
the  rapidity  of  decay  of  the  nitrogenous  substances. 
The  economical  purchase  of  these  products  depends 
largely  upon  the  judgment  of  the  farmer.  He  should 
be  guided  in  determining  their  value  by  the  amount 
of  water  contained  in  them.  As  they  approach  dry- 
ness, they  become  richer  in  the  constituents  of  fer- 
tility. In  any  case,  products  of  this  sort  should  be 
obtained  at  so  low  a  price  per  ton  as  to  guarantee  to 
the  purchaser  a  maximum  quantity  of  the  fertilizing 
constituents  for  his  money,  when  measured  by  the 
market  value  of  the  materials  of  known  composition. 

For  example,  if  crude  fish  scrap,  which  contains 
as  a  minimum  2.5  per  cent  of  nitrogen,  can  be  pur- 
chased for  $5  per  ton,  it  will  furnish  nitrogen  at  10 


WOOL   AND    EAIB    WASTH  103 

cents  per  pound,  or  at  two -thirds  the  cost  of  this 
element  in  nitrate  of  soda  at  $48  per  ton.  Besides, 
the  scrap  contains  phosphoric  acid  in  good  forms.  At 
this  price,  the  purchaser  could  afford  to  take  the  risk 
incident  to  the  variability  of  the  product. 

WOOL  AND   HAIR  WASTE 

Wool  and  hair  waste  have  already  been  described 
in  part,  though  more  largely  from  the  manufacturers' 
standpoint,  as  representing  materials  that  may  be 
utilized  in  the  manufacture  of  commercial  fertilizers. 
These  products  may  frequently  be  obtained  in  large 
quantities  and  at  a  low  price  per  ton  in  towns  in  which 
the  original  products  are  used  in  manufacturing,  and 
thus  occur  as  wastes.  Both  are  extremely  variable  in 
their  composition,  the  wool,  particularly,  being  very 
liable  to  change  in  this  respect,  owing  both  to  the 
admixture  of  non- nitrogenous  substances,  such  as 
cotton,  and  to  the  source  of  the  waste  itself, 
whether  it  consists  of  the  clippings  and  tags  from  the 
original  fleece,  or  whether  it  is  in  part  the  manu- 
factured product.  Different  samples  show  a  wide  range 
in  the  content  of  nitrogen  and  potash,  from  2  to  10 
per  cent  in  the  former,  and  from  1  to  3  per  cent  in 
the  latter.  The  nitrogen  in  the  waste  is  extremely 
slow  in  its  action  in  the  soil,  though  it  may  be  made 
directly  useful,  both  as  an  absorbent  of  other  wastes, 
as  in  liquid  manure,  and  as  an  ingredient  of  com- 
posts. Excessive  quantities  must  be  applied  in  order 
to  obtain  a  marked  immediate  result. 


104  FERTILIZERS 

The  hair  waste  is  also  variable,  both  on  account  of 
the  content  of  moisture,  as  well  as  the  admixture  with 
it  of  other  substances. 

Lime  often  occurs  as  a  waste  product  in  some 
industries,  and  as  such  it  is  frequently  wet  and  pasty, 
and  not  easily  handled. 

These  wastes,  when  they  can  be  purchased  at  a  low 
price  per  ton, — and  frequently  they  may  be  obtained 
as  low  as  two  or  three  dollars, — serve  an  excellent 
purpose  as  absorbents,  and  for  use  in  orchards  and 
pastures,  or  in  gradually  building  up  the  fertility  of 
poor  soils. 

POULTRY  AND  PIGEON  MANURES 

These  products  accumulate  in  considerable  amounts 
on  many  farms,  and  are  often  more  highly  valued 
than  their  composition  warrants.  Many  believe  that 
they  can  be  favorably  compared  with  high-grade  com- 
mercial fertilizers.  The  good  results  obtained  are 
doubtless  due  to  the  readily  available  form  in  which 
the  nitrogen  exists,  since  the  examination  of  these 
products  does  not  show  them  to  be  particularly  rich 
in  nitrogen,  or  in  the  mineral  elements  of  fertility, 
phosphoric  acid  and  potash. 

Chicken  manure  in  the  fresh  state  contains  from 
50  to  60  per  cent  of  water,  from  1  to  1.5  per  cent  of 
nitrogen,  and  about  .50  to  .75  each  of  phosphoric  acid 
and  potash.  When  brought  to  the  air-dry  state, — that 
is,  if  allowed  to  thoroughly  dry  in  the  air, — it  contains 
from  10  to  20  per  cent  of  water,  and  the  content  of 


SEWAGE  105 

the  fertilizing  constituents  is  about  doubled.  Thus, 
even  in  the  best  condition,  these  products  compare 
favorably  with  commercial  fertilizers  only  in  their 
content  of  nitrogen.  Naturally  they  also  vary  in 
their  composition,  according  to  the  character  of  food 
used  in  their  production. 

Pigeon  manure  differs  but  little  from  hen  manure 
in  composition,  though  usually  it  is  much  drier  and 
somewhat  richer  in  nitrogen. 

These  products  should  be  cared  for,  since  the  con- 
stituents in  them  serve  quite  as  well  in  the  feeding 
of  plants  as  those  contained  in  the  more  concentrated 
forms,  though  a  higher  estimation  should  not  be  placed 
upon  the  constituents  than  upon  those  contained  in 
commercial  forms  which  are  quite  as  good. 

SEWAGE 

In  recent  years,  great  progress  has  been  made  in 
the  handling  of  sewage  from  cities,  and  there  is  now 
a  product  called  "sewage  sludge,"  which  is  obtained 
in  many  towns,  as  a  result  of  its  chemical  treatment. 
Such  examinations  as  have  been  made  of  this  product 
show  it  to  be  very  poor  in  the  fertilizing  constituents, 
showing  less  than  .20  per  cent  nitrogen,  .05  phosphoric 
acid,  and  .05  potash.  It  is  seldom  worth  the  handling. 
The  untreated  sewage  and  garbage  wastes  are  also 
obtainable  in  large  quantities,  and  while  the  con- 
stituents- contained  in  them  act  quickly,  and  while 
they  are  considerably  richer  in  these  than  the  sludge 
wastes,   it   seldom   pays   the   farmer    to   handle   them, 


106  FERTILIZERS 

owing  to    their  offensive  character  and   the  enormous 
amount  of  useless  moisture  contained  in  them. 


MUCK  AND   PEAT 

"On  many  farms  there  are  low,  wet  places,  where 
the  conditions  are  favorable  for  the  collection  of 
partially  decayed  vegetable  matter.  The  material  thus 
formed  is  called  muck  or  peat.  The  thickness  of  the 
deposit,  and  its  character,  depend  upon  the  time  during 
which  it  has  been  formed,  and  the  character  of  the 
climate."  * 

Muck  is  used  mainly  as  a  source  of  humus,  and 
serves  an  excellent  purpose  as  an  absorbent  in 
cattle  stalls  or  yards.  Fresh  muck,  while  varying  in 
composition  according  to  its  source,  may  be  said  to 
contain  on  the  average  75  per  cent  of  water  and 
about  .75  per  cent  of  nitrogen,  and  only  traces  of 
potash,  phosphoric  acid  and  lime.  Air -dry  muck  also 
varies  in  composition,  largely  owing  to  the  different 
proportions  of  vegetable  and  mineral  matter  contained 
in  the  different  products,  as  well  as  the  amount  of 
water  absorbed  in  its  dry  state.  The  richer  it  is  in 
vegetable  dry  matter,  the  richer  in  nitrogen.  The 
value  of  the  muck  as  a  source  of  humus  is  measured 
by  its  content  of  nitrogen,  while  its  value  as  an  ab- 
sorbent depends  upon  its  content  of  organic  matter. 
The  value  of  muck  for  either  of  these  purposes  is 
further  modified  by  the  labor  necessary  to  secure  it  in 


*  Voorhees,  "First  Principles  of  Agriculture." 


KING    CBAB— MUSSELS  107 

a  dried  condition.     This  product   is   of    doubtful  value 
as  a  source  of  immediately  available  nitrogen. 

"The  usual  method  of  securing  it  is  to  throw  it 
out  of  the  bed  into  heaps,  and  allow  it  to  dry  before 
it  is  used,  either  upon  the  field  or  in  the  stables. 
Where  a  muck  bed  exists  upon  a  farm,  it  should  first 
be  studied  in  reference  to  its  possible  drainage.  If  it 
can  be  drained,  it  is  liable  to  prove  more  useful  where 
it  lies  than  for  the  other  purposes  mentioned."  * 

KING  CRAB,    MUSSELS   AND   LOBSTER   SHELLS 

King  crab,  already  described  in  the  discussion  of 
nitrogenous  fertilizing  materials  (page  43),  is  also 
used  in  many  section's  of  New  Jersey  in  its  green  or 
fresh  state,  either  directly  on  the  land  or  in  the  form 
of  a  compost,  and  because  of  its  nitrogenous  charac- 
ter, and  its  tendency  to  rapid  decay,  is  a  valuable 
source  of  this  element,  of  which,  in  its  fresh  state,  it 
contains  from  2  to  2.5  per  cent. 

In  certain  sections  of  the  coast  states  farmers  have 
access  to  an  almost  unlimited  supply  of  mussels,  which 
may  be  had  for  the  carting.  Analyses  made  at  the 
New  Jersey  Experiment  Station  show  them  to  contain, 
in  their  natural  state,  a  very  considerable  amount  of 
fertilizing  constituents,  the  nitrogen  reaching  .90  per 
cent,  the  phosphoric  acid  and  potash  .12  and  .13  per 
cent,  respectively,  and  the  lime  15.84  per  cent. 
The   organic    portions    of   the   mussels   decay  rapidly, 


*" First  Principles  of  Agriculture." 


108  FEBTILIZEBS 

and  serve  as  a  fairly  good  source  of  nitrogen ;  and 
since  this  product  is  twice  as  rich  in  this  constituent 
as  average  yard  manure,  it  is  well  worth  the  expense 
of  handling. 

Lobster  shells  are  also  a  waste  of  considerable  im- 
portance, since  they  can  be  obtained  at  a  very  low  cost, 
often  for  the  carting.  They  contain,  in  their  drj^  state, 
an  average  of  over  4  per  cent  of  nitrogen,  3  per  cent 
of  phosphoric  acid,  and  about  20  per  cent  of  lime. 

These  products,  of  course,  are  not  to  be  depended 
upon  for  the  entire  supply  of  constituents  to  crops  ; 
they  are  mainly  useful  in  improving  the  natural  quality 
of  the  soil  by  building  it  up  in  vegetable  matter  con- 
taining nitrogen.  Their  best  use  requires  the  addition 
of  the  minerals  from  other  sources. 


SEAWEED 

In  the  coast  states,  seaweed  is  held  in  high  esteem 
as  a  manurial  product.  In  Connecticut,  Rhode  Island 
and  New  Jersey,  the  use  of  seaweed  as  a  fertilizer  is 
very  general.  In  Rhode  Island  the  annual  value  of  the 
manure  from  this  source  has  been  estimated  to  be  as 
high  as  $65,000.* 

In  its  fresh  state  it  contains  from  70  to  over  80  per 
cent  of  water,  and  is  thus  economically  used  in  that 
condition  only  near  the  shore.  It  is  frequently  spread 
out  in  thin  layei-s  and  dried,  in  which  condition  it  can 
be  profitably  transported  considerable  distances. 


*  Bnlletin  21,  Rhode  Island  Exi>eriment  Station. 


WOOD   ASHES  109 

Seaweeds  of  different  kinds  differ  in  their  content 
of  the  fertilizing  constituents.  Certain  of  them  show 
a  relatively  high  content  of  nitrogen,  and  others  of 
potash,  and  they  furnish  more  of  these  constituents 
than  of  phosphoric  acid.  All  seaweeds  contain  con- 
siderable salt,  though  if  they  are  not  used  in  too  large 
quantities,  no  serious  injury  is  liable  to  follow.  In 
fact,  salt  in  some  instances  is  a  substance  of  con- 
siderable indirect  manurial  value.  Seaweed  manure 
is  certainly  worthy  of  consideration  where  it  can  be 
obtained  in  quantity  for  the  expense  of  carting. 

WOOD    ASHES     AND     TAN -BARK    ASHES 

Wood  ashes  contain  potash  in  one  of  the  best  forms, 
and  were,  in  the  early  history  of  manuring,  practi- 
cally the  only  semi -artificial  source  of  this  element. 
At  the  present  time,  however,  the  supply  is  limited, 
and  the  average  content  of  potash  in  the  commercial 
article  is  much  lower  than  was  formerly  the  case. 

The  pure  ash  is  not  a  uniform  product.  That  from 
the  different  varieties  of  wood  varies  in  composition. 
As  a  rule,  the  softer  woods  are  poorer  and  the  hard 
woods  richer  in  potash  than  the  average,  the  range 
being  from  16  to  40  per  cent. 

"Ashes  also  contain  lime  in  large  quantities,  while 
phosphoric  acid  is  contained  in  much  smaller  quanti- 
ties. Wood  ashes,  as  usually  gathered  for  market, 
however,  contain  very  considerable  proportions  of  mois- 
ture, dirt,  etc.,  which  cause  a  variability  in  composition 
not  due  to  the  character  of  the  woods  from  which  they 


110  FERTILIZERS 

are  derived.  The  average  analysis  of  commercial  wood 
ashes  shows  them  to  contain  less  than  6  per  cent  of 
potash,  2  of  phosphoric  acid  and  32  per  cent  of  lime. 
Leached  wood  ashes  contain  on  the  average  30  per  cent 
of  moisture,  1.10  of  potash,  1.50  of  phosphoric  acid 
and  29  per  cent  of  lime. 

"Ashes  are  probably  one  of  the  best  sources  of 
potash  that  we  have,  so  far  as  its  form  and  combina- 
tion are  concerned,  being  in  a  very  fine  state  of  divi- 
sion, and  in  such  a  form  as  to  be  immediately  available 
to  plants.  Ashes  also  have  a  very  favorable  physical 
effect  upon  soils,  the  lime  present,  of  course,  aiding  in 
this  respect.  Canada  is  now  the  main  source  of  wood 
ashes,  the  substitution  of  coal  for  wood  making  the 
supply  in  this  country  for  commercial  purposes  very 
limited.  Owing  to  the  variability  of  this  product,  it 
should  always  be  bought  subject  to  analysis,  and  to  a 
definite  price  per  pound  for  the  actual  constituents 
contained  in  it,  which  should  not  be  greater  than  the 
price  at  which  the  same  constituents  could  be  pur- 
chased in  other  quickly  available  forms."  * 

Tan -bark  ashes  are  much  poorer  in  fertilizing 
content  than  those  obtained  from  the  regular  com- 
mercial sources  of  supply.  They  seldom  contain  more 
than  2  per  cent  of  potash,  1.5  per  cent  of  phosphoric 
acid  and  33  per  cent  of  lime. 

Lime -kiln  ashes  are  obtained  in  the  burning  of 
lime  with  wood,  and  are  also  relatively  poor  in  potash, 
containing  less  than  1.5  per  cent  of  potash  and  1  per 

♦"First  Principles  of  Agriculture." 


COAL   AND    COTTON-HULL   ASHES  HI 

cent  of  phosphoric  acid.  The  product  is,  however, 
much  richer  in  lime  than  the  average  wood  ashes,  often 
containing  as  high  as  50  per  cent  of  calcium  oxide. 

COAL  ASHES ' 

It  is  believed  by  many  that  coal  ashes,  because  of 
their  favorable  effect  upon  many  soils,  also  possess 
considerable  fertilizing  value,  whereas  analyses  show 
them  to  contain  only  traces  of  soluble  potash  and  of 
phosphoric  acid.  The  good  results  from  their  use  is 
undoubtedly  due  to  their  beneficial  indirect  effect  in 
improving  the  physical  character  of  heavy  soils. 


COTTON -HULL  ASHES 

Cotton -hull  ashes  were  formerly  made  in  consid- 
erable quantities  in  the  southern  states,  where  the 
hulls  were  used  as  fuel  in  the  furnaces  connected  with 
gins  and  presses.  This  product,  while  exceedingly 
variable  in  composition,  is  usually  very  rich  in  potash, 
besides  containing  a  very  considerable  amount  of 
available  phosphoric  acid.  A  large  number  of  samples 
have  been  examined  at  the  Connecticut  Experiment 
Station,*  and  the  results  of  the  study  show  that  no 
average  percentage  composition  is  a  sufficient  guide 
as  to  their  quality.  They  can  be  safely  purchased 
only  on  the  basis  of  their  actual  composition.  They 
are  an  excellent  source  of  potash  and  phosphoric  acid, 


*Annual  Report  for  1897  (Part  II.),  Connectictit  Experiment  Station. 


112  FERTILIZERS 

because  free  from  cMorids  and  other  deleterious  sub- 
stances, but  are  not  so  rich  in  lime.  They  are  espe- 
cially useful  for  such  crops  as  are  injured  by  the 
presence  of  chlorids. 

MAEL* 

Marl  may  contain  one  or  more  of  the  constituents, 
phosphoric  acid,  potash  and  lime.  Shell  marls  are 
usually  very  rich  in  lime,  but  contain  only  traces  of 
phosphoric  acid  and  potash.  The  green  sand  marls  of 
New  Jersey  often  contain  very  considerable  amounts 
of  phosphoric  acid  and  potash,  though  they  vary 
widely  in  composition.  They  contain,  on  the  average, 
2.20  per  cent  of  phosphoric  acid,  4.70  per  cent  of 
potash,  and  2,90  per  cent  of  lime.  These  constituents, 
particularly  the  potash,  are,  as  a  rule,  slowly  available. 

Marl,  however,  is  an  important  amendment  to  soils, 
not  only  because  of  its  content  of  mineral  constituents, 
but  because  these  constituents  are  associated  with 
products  that  exert  a  very  favorable  mechanical  effect 
upon  soils.  Large  areas  of  land  in  the  state  of  New 
Jersey,  formerly  unproductive,  chiefly  because  of  phy- 
sical imperfections,  have  been  made  very  productive 
mainly  through  the  application  of  marl. 

The  use  of  marl  is  now  less  general  than  when  the 
fertilizing  constituents  from  artificial  sources  were 
dearer,  and  when  the  labor  of  the  farm  was  more 
abundant  and  cheaper.  The  quicker  effect  of  more 
soluble  fertilizer   constituents  has  had  an  influence  in 


*  "First  Principles  of  Agrietilture." 


LIMJi]  113 

reducing  the  use  of  marl  where  quick  returns  are 
desirable.  Where  farmers  have  deposits  of  marl  upon 
their  own  farms,  or  within  short  distances  of  them, 
and  can  secure  it  at  a  low  price  per  ton,  its  ap- 
plication is  a  desirable  method  of  improving  land. 

The  results  from  the  use  of  marl  are  frequently  due 
quite  as  much  to  the  improvement  given  to  the  phy- 
sical condition  of  soils  as  to  the  increase  in  fertility 
furnished  by  the  essential  mineral  constituents.  Marl 
may  be  carted  and  spread  upon  the  land  when  other 
work  of  the  farm  is  not  pressing,  thus  making  it 
possible  to  get  a  considerable  addition  of  fertility  at  a 
small  expense. 

LIME 

"Lime,  as  it  is  generally  known,  is  an  oxide  of 
calcium,  and  is  produced  by  burning  limestone,  or 
carbonate  of  lime.  The  lime  loses  the  carbonic  acid 
when  burned  in  the  kilns,  and  the  oxide  of  lime 
remains  behind;  this  is  termed  'burned  lime,'  'quick- 
lime,' or  'stone  lime,'  and  is  usually  slaked  before 
it  is  applied  to  the  soil.  This  is  done  by  adding 
water,  which  the  lime  absorbs,  and  falls  to  a  powder. 
Slaked  lime,  also  called  caustic  lime,  is  a  calcium 
hydrate. 

"The  more  completely  limestone  is  burned,  the 
better  the  quicklime,  and  the  more  completely  it 
slakes.  We  have,  when  we  speak  of  lime,  three 
forms:  limestone,  quicklime  and  slaked  lime,  each  dif- 
fering  from  the  other  in  composition. 

H 


114  FERTILIZERS 

"Quicklime  absorbs  moisture,  and  slakes  when 
exposed  to  the  atmosphere.  Lime  thus  slaked  is 
called  'air-slaked  lime,'  and  is  usually  less  com- 
pletely changed  to  a  hydrate  than  when  water  is 
added.  Quicklime  also  absorbs  carbonic  acid  from 
the  air,  and  changes  back  to  the  limestone  form. 
Lime  in  the  carbonated  form,  if  finely  pulverized,  is 
better  for  liming  light  lands  than  the  caustic  lime, 
while  for  heavy  lands,  the  caustic  is  preferable  to 
the  carbonate."* 

What  is  termed  "marble  lime"  is  made  from  pure 
limestone,  and  the  burned  lime  thus  obtained  is  prac- 
tically pure  oxide  of  lime.  Limestone,  so  called,  is 
not  always  pure.  It  is  a  mixture  of  lime  and  mag- 
nesia, in  which  case  it  is  the  mineral  "dolomite,"  and 
is  termed  "magnesian  limestone."  A  very  large 
quantity  of  the  lime  used  in  the  eastern  states  is  the 
magnesian  form.  The  burned  lime  from  the  magne- 
sian limestone  contains  from  50  to  60  per  cent  of 
calcium  oxide,  and  30  per  cent  or  over  of  magnesium 
oxide.  In  some  instances,  the  magnesia  is  of  value, 
though  it  is  rather  inert  in  its  effect,  and  is  less  use- 
ful than  the  lime.  A  safe  rule  in  the  purchase  and 
use  of  lime  is  to  adjust  the  price  to  the  proportionate 
percentage  of  actual  lime  present,  or  practically  in 
the  ratio  of  10  to  7. 

Oyster  shells  are  nearly  pure  carbonate  of  lime, 
and  oyster  shell  lime,  while  practically  pure  lime,  so 
far  as  this  element  is  concerned,  is  usually  mixed  with 


*"  First  Principles  of  Agrietilture." 


GAS   LIME   AND    GYPSUM  115 

more  or  less  dirt  and  other  impurities,  and  is,  there- 
fore, not  as  rich  in  lime  as  that  derived  from  pure 
limestone. 

"  Gas  lime  is  also  frequently  used  as  manure  ;  in 
gas  works,  quicklime  is  used  for  removing  the  impuri- 
ties from  the  gas.  Gas  lime,  therefore,  varies  con- 
siderably in  composition,  and  consists  really  of  a  mix- 
ture of  slaked  lime,  or  calcium  hydrate,  and  carbo- 
nate of  lime,  together  with  sulfites  and  sulfides  of  lime. 
These  last  are  injurious  to  young  plant  life,  and  gas 
lime  should  be  applied  long  before  the  crop  is  planted, 
or  at  least  exposed  to  the  air  some  time  before  its 
application.  The  action  of  air  converts  the  poisonous 
substances  in  it  into  non- injurious  products.  Gas 
lime  contains  on  an  average  40  per  cent  of  calcium 
oxide,  and  usually  a  small  percentage  of  nitrogen."* 

Where  it  can  be  used  to  advantage,  its  cost  should, 
as  in  the  case  of  the  other,  be  based  on  the  proportion 
of  actual  lime  present. 

Gypsum  is  a  sulfate  of  lime,  containing  water  in 
combination.  Pure  gypsum  contains  32.5  per  cent  of 
lime,  46.5  per  cent  of  sulfuric  acid,  and  21  per  cent 
of  water. 

Plaster  of  Paris  is  prepared  from  gypsum  by  burn- 
ing, which  drives  off   the  water  it  contains. 

Gypsum,  like  other  forms  of  lime,  furnishes  directly 
the  element  calcium,  and  also  exerts  a  favorable  solvent 
effect  upon  the  soil.  It  was  formerly  used  in  large 
quantities,  particularly  for  clover,  and   it    is   believed 


*"  First  Principles  of  Agriculture." 


116  FEBTILIZEBS 

that  its  favorable  effect  was  due,  not  so  much  to  the 
direct  addition  of  lime,  as  to  its  action  upon  insoluble 
potash  compounds  in  the  soil,  in  setting  free  potash. 
Thus  the  application  of  plaster  caused  an  increase  in 
crop,  because  of  the  potash  made  available. 

We  have  in  the  eastern  states  two  main  sources 
of  gypsum,  namely.  Nova  Scotia  and  Cayuga,  N.  Y, 
Nova  Scotia  plaster  contains  on  the  average  over 
90  per  cent  of  sulfate  of  lime,  and  is,  therefore, 
purer  than  that  obtained  from  Cayuga,  which  often 
shows  as  low  as  65  per  cent  of  pure  sulfate;  the 
latter,  however,  frequently  contains  appreciable  amounts 
of   phosphoric  acid. 

In  many  places,  it  is  possible  to  obtain  plaster 
which  is  a  waste  in  the  manufacture  of  phosphorus. 
This  waste  contains  the  plaster  in  a  precipitated  form, 
and  frequently  also  contains  considerable  amounts  of 
phosphoric  acid.  The  disadvantage  of  this  waste  lies 
in  the  fact  that  it  is  frequently  wet  and  lumpy,  and 
thus  not  easily  handled  and  distributed.  Its  advan- 
tage lies  in  its  content  of  phosphoric  acid,  which 
ranges  from  1.5  to  2  per  cent,  though  as  a  rule,  it  can 
be  purchased  at  a  lower  price  per  ton  than  that  from 
the  regular  sources. 

AGRICULTURAL    SALT 

Agricultural  salt,  which  is  chiefly  common  salt,  is 
also  frequently  used  as  a  manure.  "It  supplies  no 
essential  plant -food  constituents,  and  its  value  is  still 
a  disputed  point,  though  it  is  admitted  that  where  its 


SALT   AND    POWDER    WASTE  117 

use  is  favorable,  it  is  due  to  indirect  action  in  aiding 
the  decomposition  of  animal  and  vegetable  matter, 
increasing  the  absorbing  power  of  soils,  and,  by  its 
reaction  with  lime,  acting  as  a  solvent  for  phosphates."* 
There  would  seem  to  be  no  good  reason  for  paying 
from  $4  to  $6  per  ton  for  this  substance,  when  prac- 
tically the  same  eifect  can  be  obtained  from  the  salt 
contained  in  the  crude  potash  salt,  kainit,  one -third 
of  the  total  weight  of  which  is  common  salt.  This, 
too,  may  be  had  free  of  charge,  or  for  the  handling, 
as  the  market  price  of  the  kainit  is  based  upon  its 
content  of  potash. 

POWDER   WASTE 

Powder  waste  also  consists  largely  of  common  salt, 
though  frequently  containing  appreciable  percentages 
of  nitrogen  in  the  form  of  a  nitrate.  Its  use  can 
only  be  recommended  when  it  can  be  obtained  at  a 
low  price  per  ton,  or  for  the  handling,  and  upon  soils 
that  show  a  marked  benefit  from  its  application. 

GREEN  MANURES 

A  great  deal  of  misconception  is  prevalent  con- 
cerning the  value  of  what  are  termed  "green  manures." 
These  do  possess  a  distinct  value,  and  a  proper  under- 
standing of  their  place  in  farm  management  will 
undoubtedly  result  in   their  larger  and  better  use,  and 


•"First  Principles  of  Agriculture." 


118  FEBTILIZEB8 

in  the  consequent  improvement  of  agricultural  prac- 
tice. By  green  manures  is  meant  any  crop  that  is 
grown  primarily  for  the  purpose  of  improving  the 
soil,  and  not  for  the  harvested  product. 

"  Nitrogen  Gatherers  "  and  "  Nitrogen  Consumers  " 

In  this  sense  any  crop  will  serve  as  a  green 
manure,  yet  certain  crops  possess  a  greater  value  than 
others  for  this  purpose,  because  they  are  able  to  obtain 
certain  of  their  constituents  from  sources  not  acces- 
sible to  all  crops.  In  other  words,  the  one  class  of 
plants  can  obtain  the  nitrogen  necessary  for  their 
growth  from  the  air,  as  well  as  from  the  soil;  the 
other,  as  far  as  we  now  know,  can  obtain  it  only 
from  the  soil.  These  two  groups  of  plants  are,  there- 
fore, classified  as  "nitrogen  gatherers"  and  "nitrogen 
consumers." 

The  nitrogen  gatherers  belong  to  the  legume,  or 
clover  family,  and  do  not  depend  solely  upon  soil 
sources,  but  rather  gather  the  element  from  outside, 
and  thus  do  not  reduce  the  content  of  soil  nitrogen. 
Distinguishing  features  of  the  plants  of  this  order 
are  that  the  seeds  are  formed  in  a  pod  or  legume,  and 
that  they  have  the  power  of  acquiring  at  least  a  large 
part  of  their  nitrogen  from  the  air.  These,  when 
plowed  down  as  green  manures,  add  directly  to  the 
crop -producing  capacity  of  soils  poor  in  nitrogen, 
because  increasing  their  content  of  this  element.  In 
order  that  the  plant  may  obtain  its  nitrogen  from 
the  air,   however,  the  soil  must  originally  contain,  or 


TH£}  ADVANTAGES   OF   GBEEN  MANUBES       119 

must  be  inoculated  with,  a  specific  germ,  the  presence 
of  which  is  manifested  by  the  growth  of  nodules 
upon  the  roots,  through  which  it  is  believed  the 
nitrogen  is  obtained.  Most  well -tilled  soils  contain 
these  germs  in  abundance. 

The  "nitrogen  consumers"  are  those  which  can 
obtain  their  nitrogen  only  from  the  soil ;  these  con- 
sume the  nitrogen  existing  there,  and  their  growth 
and  removal  exhausts  the  soil  of  this  element. 

Notwithstanding  the  w&ry  great  advantages  of  the 
"nitrogen  gatherers"  as  green  manures,  they  cannot 
be  solely  depended  upon  to  increase  the  crop -produc- 
ing capacity  of  the  soil.  That  is,  soils  that  are  very 
poor,  both  in  their  content  of  nitrogen  and  of  the 
essential  mineral  elements,  cannot  be  made  very  pro- 
ductive by  the  sole  use  of  green  manures.  In  fact, 
the  green  manure  crops  cannot  be  grown  with  ad- 
vantage unless  they  are  supplied  with  an  abundance 
of  the  mineral  elements,  phosphoric  acid  and  potash  ; 
hence  helpful  green  manuring  for  such  soils  must  be 
preceded  and  accompanied  by  liberal  fertilization  with 
the  minerals,  phosphoric  acid,  potash  and  lime.  With 
these  added  in  sufficient  amounts,  and  with  the  specific 
bacteria  present  in  the  soil,  their  use  results  not  only 
in  the  addition  of  nitrogen  to  the  soil,  which  may  be 
useful  for  other  plants,  but  by  the  accumulation  of 
vegetable  matter,  which  improves  the  physical  char- 
acter, usually  imperfect  in  this  class  of  soils.  The 
nitrogen  thus  introduced  into  the  soil  is  also  in  a  very 
good  form;  that  is,  it  has  a  tendency  to  decay  rap- 
idly and   thus   supply  the   needs   of    other   plants,  but 


120  FERTILIZERS 

the  helpful  additions  to  the  soil  are  limited  to  organic 
matter  and  nitrogen.  The  mineral  constituents  ab- 
sorbed by  the  crop  may  be  more  available  for  other 
crops,  but  they  formerly  existed  there.  No  additions 
of  these  are  made  by  the  growing  of  the  crop ;  hence 
no  system  of  green  manuring  can  be  made  successful 
unless  chere  is  a  previous  abundance  in  the  soil  of  the 
mineral  elements,  or  unless  these  have  been  directly 
applied. 

The  Most  Useful  Crops 

Of  the  crops  most  useful  for  green  manures,  red 
clover,  crimson  clover,  cow  peas  and  soja  beans  are 
first  in  order ;  first,  because  of  their  capacity  to 
gather  nitrogen,  and  second,  because  of  their  period 
and  time  of  growth.  Whether  these  plants  will 
gather  all  of  the  nitrogen  of  their  growth  from  the 
air,  other  conditions  being  good,  depends  upon 
whether  the  soil  is  rich  or  poor  in  nitrogen,  since  it 
has  been  shown  that  these  plants  will  gather  at  least 
a  part  of  the  nitrogen  from  the  soil  in  preference  to 
that  from  the  air,  unless  they  are  starved  in  respect 
to  soil  nitrogen.  The  amounts  that  may  be  gathered 
from  the  air,  therefore,  are  not  measured  by  the  total 
content  of  nitrogen  contained  in  the  plant  grown 
(which  may,  in  the  case  of  good  crops,  amount  to  as 
much  as  200  pounds  per  acre,  sufficient  for  the  use  of 
several  good  crops  of  wheat,  or  other  cereal  grains), 
but  apparently  by  the  poverty  of  the  soil  in  this  ele- 
ment. The  fact  that  an  accumulation  of  nitrogen 
does  occur  has  been  distinctly  shown,  and  their  con- 


CROPS    USEFUL  AS   GBEEN  MANURES  121 

tinuous  growth,  therefore,  would  have  a  tendency  to 
over -enrich  the  soil  in  this  constituent,  unless  accom- 
panied by  an  abundant  supply  of  minerals,  particu- 
larly in  the  improvement  of  light  lands  and  in 
orchards  and  vineyards,  for  which  their  right  use 
is  very   beneficial. 

Experiments  conducted  in  this  as  well  as  other 
countries,  show  that  the  nitrogen  so  gathered  and 
stored  in  the  soil  may  be  readily  obtained  by  cereal 
and  other  nitrogen -consuming  crops.  In  experiments 
conducted  by  the  New  Jersey  Experiment  Station,  on 
a  poor,  sandy  soil,  in  which  the  mineral  elements, 
phosphoric  acid,  potash  and  lime,  only,  were  added, 
a  crop  of  cow  peas  gathered,  in  the  roots  and  tops, 
75  pounds  of  nitrogen,  equivalent  to  that  contained 
in  470  pounds  of  nitrate  of  soda,  which  when  turned 
under  was  capable  of  feeding  a  rye  crop  with  suf- 
ficient nitrogen  to  produce  a  most  excellent  crop, 
quite  as  good  as  that  grown  on  land  long  under  cul- 
tivation and  well -manured.  Further  experiments  con- 
ducted with  crimson  clover*  show  that  the  nitrogen 
gathered  was  capable  of  supplying  the  needs  of  fruit 
trees  quite  as  well  as  when  the  nitrogen  was  applied 
in  the  immediately  available  form  contained  in  nitrate 
of  soda. 

If  it  were  necessary  to  do  so,  numerous  experi- 
ments might  be  cited  to  show  that  the  nitrogen  is 
gathered  from  the  air  by  these  plants,  and  that  it  is 
capable  of  providing  that  required  for  those  other 
crops  which  can  obtain  it  only  from  the  soil. 

♦Annual  Report  for  1894,  New  Jersey  Experiment  Station. 


122  FERTILIZEBS 

Green  Manure  Crops  that  Consume  the  Nitrogen 
in  the  Soil 

In  addition  to  the  legumes,  other  crops  are  used 
as  green  manures,  chief  of  which  are  rye,  buckwheat 
and  mustard,  not  because  they  are  capable  of  directly 
gathering  nitrogen,  but  because  their  period  and  time 
of  growth  are  such  as  frequently  to  enable  them  to 
serve  a  very  useful  purpose  in  preventing  losses  in 
fertility.  In  the  growth  of  these  crops,  however,  the 
only  real  addition  to  the  soQ  is  the  amount  of  non- 
nitrogenous  organic  matter  contained  in  them.  The 
nitrogen  gathered  is.  in  direct  proportion  to  the 
amount  contained  in  the  soil  and  the  relative  feeding 
capacity  of  the  plant.  The  nitrogen  is  not  obtained 
from  the  atmosphere,  and  the  soil  has  not  accumu- 
lated nitrogen  by  virtue  of  their  growth,  and  is  not 
richer  in  this  element,  except  in  so  far  as  by  their 
growth  they  prevent  the  escape  of  readily  available 
nitrogen  into  the  drainage  waters.  The  nitrogen 
gathered  is  "soil  nitrogen,"  and  its  conversion  into  a 
crop  simply  results  in  changing  its  form  and  place. 
The  specific  use  of  these  crops,  therefore,  so  far  as 
directly  contributing  to  the  fertility  of  the  soil  is  con- 
cerned, is  to  prevent  the  possible  loss  of  nitrogen  and 
other  constituents  by  leaching,  which  is  more  liable 
to  occur  on  uncropped  soils,  though  they  further 
contribute  toward  soil  improvement  by  accumulating 
stores  of  non- nitrogenous  vegetable  matter. 

These  crops,  too,  in  order  that  they  may  produce 
largely,  must  be  freely  supplied  with  the  mineral  ele- 


THE  BIGHT   USE   OF   GBEEN  MANUBES  123 

ments,  as  well  as  with  nitrogen  in  some  form,  and 
cannot  be  regarded  as  a  substitute  for  the  leguminous 
crops,  or  as  a  substitute  for  commercial  fertilizers  in 
the  permanent  improvement  of  the  soil,  in  the  sense 
that  they  actually  contribute  to  its  content  of  fertility 
elements, — an  opinion  apparently  held  by  many  who 
have  observed  the  good  results  that  often  follow 
their  use. 

Furthermore,  these  crops  contain,  as  a  rule,  less 
nitrogen,  and  besides,  that  contained  in  them  is 
apparently  less  available  than  the  nitrogen  contained 
in  the  green  manures  from  the  leguminous  crops.  In 
their  growth,  too,  they  appropriate  the  immediately 
available  nitrogen  of  the  soil,  and  convert  it  into  the 
less  available  organic  form  ;  hence  the  crop  that  fol- 
lows is  frequently  unable  to  obtain  its  food  as  readily 
as  would  have  been  the  case,  provided  the  green 
manure  crop  had  not  been  grown.  Therefore,  while 
the  practice  of  using  green  manures  is  a  desirable  one 
when  properly  understood,  it  should  not  be  regarded 
as  a  means  by  which  soils  may  be  directly  enriched, 
except  in  the  case  of  the  plants  of  the  legume  family, 
where  nitrogen  is  really  added  to  the  soil.  In  the 
case  of  all  other  crops,  the  benefit  is  indirect,  and  is 
in  proportion  to  the  amount  of  minerals  added. 


CHAPTER  VII 

PURCHASE   OF  FERTILIZERS 

Commercial  fertilizers,  in  the  form  in  which  they 
are  obtained  by  farmers,  are  made  up  of  varying  pro- 
portions of  one  or  more  products  from  each  class  of 
fertilizing  materials  described.  That  is,  every  manu- 
facturer is  obliged  to  go  to  these  sources  of  supph% 
whatever  may  be  the  name  given  to  the  finished 
product  or  mixture.  Hence  the  fertilizing  materials 
described  are  not  regarded  as  commercial  fertilizers  in 
the  same  light  as  those  which  they  are  able  to  pur- 
chase under  brand  names  from  their  local  dealers.  In 
the  first  place,  a  specific  fertilizing  material,  as  dis- 
tinct from  a  manufactured  fertilizer,  contains,  as  a 
rule,  but  one  of  the  essential  fertilizing  elements,  and 
its  use  under  average  conditions  would  be  far  differ- 
ent from  one  which  contains  two  or  all  of  the  essen- 
tial fertilizing  elements.  The  materials,  therefore, 
are  classed  as  nitrogenous,  phosphatic  and  potassic, 
according  to  whether  the  material  contains  nitrogen, 
phosphoric  acid  or  potash  as  its  chief  or  its  only 
constituent  element ;  and  these  different  classes,  too, 
may  be  again  sub -divided  into  two  distinct  groups, 
the  first  including  "standard,"  or  high-grade  materials, 
and  second,  "general,"  or  low-grade  materials.  This 
classification  is  of  the  utmost  importance. 

(124) 


t 


EIGE-GBADE  FERTILIZING   MATERIALS        125 


STANDARD    HIGH-GRADE    MATERIALS 


Nitrate  of  soda,  sulfate  of  ammonia,  and  dried 
blood  are,  for  example,  standard  or  high-grade 
nitrogenous  materials,  and  belong  to  the  first  group. 
They  are  "standard"  because  they  do  not  vary  widely 
in  their  composition.  A  definite  quantity  can  be 
depended  upon  to  furnish  not  only  practically  the 
same  amount  of  the  specific  constituent,  but  to  fur- 
nish it  in  a  distinct  and  definite  form,  which  is  iden- 
tical, from  whatever  source  derived.  For  example, 
commercial  nitrate  of  soda  does  not  vary  materially 
in  its  composition,  and  the  nitrogen  in  it  is  always  in 
the  form  of  a  nitrate.  The  same  is  true  of  sulfate 
of  ammonia.  One  ton  will  furnish  practically  as  much 
nitrogen  as  any  other  ton,  and  it  is  always  in  the 
form  of  ammonia.  It  is  also  practically  true  of  high- 
grade  dried  blood.  Each  lot  contains  this  specific  form 
of  organic  nitrogen,  and  will  always  decay  at 
practically  the  same  rate,  if  used  under  the  same 
conditions.  They  are  also  high-grade  products  because 
they  are  richer  in  the  constituent  element,  nitrogen, 
than  any  other,  and  because  this  element  is  im- 
mediately or  quickly  available. 

The  South  Carolina,  Florida  and  Tennessee  rock 
phosphates  differ  from  the  nitrogenous  materials  men- 
tioned, inasmuch  as,  in  their  raw  state,  they  are  not 
directly  useful  as  fertilizers, —  they  are  not  sources 
of  available  phosphoric  acid.  Hence  the  standard 
supplies  of  phosphoric  acid  are  derived  from  these 
materials  after  they  are  manufactured  into  superphos- 


126  FERTILIZERS 

phates.  The  various  kinds  of  these  may  be  regarded 
as  high-grade  in  the  sense  that  they  always  possess 
a  high  content  of  available  phosphoric  acid.  They 
are  standard,  too,  not  only  because  of  this,  but 
because  they  do  not  vary  widely  in  their  composi- 
tion. A  definite  amount  from  each  class  can  be  de- 
pended upon  to  furnish  practically  the  same  amount 
of  available  phosphoric  acid.  For  example,  a  ton  of 
South  Carolina  rock  superphosphate,  from  whatever 
manufacturer  obtained,  will  not  vary  widely  in  its 
content  of  phosphoric  acid,  and  will  always  act  in 
the  same  way  under  similar  conditions.  The  various 
German  potash  salts  are  also  standard  and  high-grade, 
since  the  composition  of  each  grade  and  kind  is 
practically  uniform  in  its  content  of  potash,  which 
will  always  act  in  the  same  way  under  the  same  con- 
ditions, and  since  they  are  richer  in  the  specific  ele- 
ment, potash,  than  other  potassic  compounds  suitable 
for  the  manufacture  of   fertilizers. 

These  various  standard,  high-grade  products,  when 
used  in  the  manufacture  of  fertilizers,  make  what  are 
called  "chemical  fertilizers,"  because  they  are  really 
crude  chemical  compounds,  and  furnish  the  particular 
fertilizer  elements  in  their  most  concentrated  and 
active   forms. 

FERTILIZING    MATERIALS    WHICH    ARE    VARIABLE    IN 
COMPOSITION 

The  products  which  are  included  in  the  second 
group   differ  from   the   others,   in  that  they  not  only 


VABIABILITY    OF  LOW-GBADU    MATHBIALS     127 

vary  in  their  content  of  the  specific  constituent,  or 
in  their  composition,  but  they  are  also  variable  in  the 
sense  that  the  constituents  contained  in  them  do  not 
show  a  uniform  rate  of  availability.  For  example, 
ground  bone  varies  in  its  composition  owing  to  its 
source  and  the  method  of  treatment,  and  the  availa- 
bility of  the  constituents,  nitrogen  and  phosphoric 
acid,  also  varies  because  of  these  conditions,  and 
because  of  its  mechanical  condition  or  degree  of 
fineness.  Different  samples  of  bone  derived  from  the 
same  source,  treated  in  the  same  way,  and  ground 
to  the  same  degree  of  fineness,  would  be  regarded  as 
standard,  but  because  these  conditions  differ,  bone 
from  different  sources  cannot  be  depended  upon  to 
act  in  the  same  way  under  the  identical  climatic  and 
soil  conditions.  This  is  also  true  of  tankage,  which 
varies,  not  only  in  the  total  amount  of  the  constitu- 
ents contained  in  it,  but  in  the  proportion  of  its  two 
chief  constituents,  nitrogen  and  phosphoric  acid,  and 
in  the  rate  at  which  they  become  available  to  plants. 
In  this  class  belong,  in  addition  to  the  bone  and 
tankage,  ground  fish,  and  the  various  miscellaneous 
products.  They  cannot  be  depended  upon,  either  in 
respect  to  their  composition  or  their  availability  of 
the  essential  constituents  —  important  advantages  pos- 
sessed by  the  standard  products. 

HIGH-GRADE   AND  LOW-GRADE   FERTILIZERS 

The  fertilizers  manufactured  from  these  two  classes 
of    raw   materials   will,  therefore,  differ.     Those  made 


128  FERTILIZERS 

from  the  first  class  are  always  high-grade,  both  in 
reference  to  the  quality  and  quantity  of  the  constituents 
that  may  be  contained  in  a  mixture.  Those  manu- 
factured from  the  second  group  are  not  high-grade, 
so  far  as  the  form  of  the  constituent  is  concerned, 
though  they  may  be  high-grade  in  the  sense  that  they 
contain  large  amounts  of  them.  In  the  manufacture 
of  fertilizers,  too,  as  a  rule,  all  three  of  the  essential 
constituents  are  introduced,  and  the  buying  of  a  fer- 
tilizer is  really  the  buying  of  the  three  constituents, 
nitrogen,  phosphoric  acid  and  potash.  Hence,  the 
more  concentrated  the  product,  or  the  richer  it  is  in 
these  constituents,  the  less  will  be  the  actual  cost  of 
handling  per  unit  of  the  constituents  desired,  and  the 
higher  the  grade  of  the  materials  used,  the  greater 
the  proportionate  activity  of  the  constituents. 

The  "  Unit "  Basis  of  Purchase 

In  commercial  transactions  in  fertilizing  materials, 
two  systems  of  purchase  are  used.  The  first  is  known 
as  the  "unit"  system,  in  which  case  the  quotations,  or 
prices  are  based  on  the  unit,  A  unit  means  one 
per  cent  on  the  basis  of  a  ton,  or  20  pounds.  For 
example,  a  unit  of  available  phosphoric  acid  means 
20  pounds,  and  a  quotation  of  $1  per  unit  would  be 
equivalent  to  a  quotation  of  5  cents  per  pound.  In 
the  trade,  sales  are  always  made  on  this  basis.  The 
system  is  also  applied  to  such  nitrogenous  products  as 
blood,  meat,  hoof  meal,  concentrated  tankage,  etc. 
The   price   is   fixed   at   so   much   a  unit   of   ammonia. 


«  UNIT"  AND    «  TON"   BASES    OF   PURCHASE     129 

This  system  is  probably  the  most  perfect,  and  certainly 
cannot  but  be  satisfactory  to  both  the  dealer  and  the 
consumer.  It  results  in  the  consumer  receiving  exactly 
as  much  as  he  pays  for,  and  the  producer  is  paid  for 
exactly  what  he  delivers.  The  number  of  units  in 
each  material  sold  is  fixed  in  each  case  by  the  chemist 
to  whom  the  samples  are  referred. 

The  "  Ton "  Basis  of  Purchase 

The  other  method  of  purchase  is  known  as  the  "  ton 
basis,"  and  is  used  almost  exclusively  in  the  sale  of 
other  materials  than  the  standard  products  mentioned, 
and  manufactured  fertilizers.  This  system  works  well 
with  standard  high-grade  products,  since  the  ton  price 
is,  in  this  case,  a  fair  guide  as  to  the  cost  of  the  con- 
stituents, though  it  cannot  be  as  satisfactory  as  the 
other,  since  even  the  best  materials  may  vary  sufB- 
ciently  to  cause  a  difference  in  actual  cost  of  the 
constituents,  even  though  the  price  per  ton  remains 
unchanged.  In  this  method,  the  products  are  usually 
accompanied  by  a  guarantee,  the  purpose  of  which  is 
to  indicate  the  minimum  amount  of  the  constituents 
contained  in  the  material. 

The  Necessity  of  a  Guarantee 

In  the  purchase  of  mixtures,  consumers  should 
demand  that  they  be  accompanied  by  a  guarantee, 
because  they  are  unable  to  determine  the  kind  and 
proportion    of    the    different    materials    entering    into 


130  FERTILIZERS 

the  mixture,  either  by  its  appearance,  weight  or  smell. 
In  mixing,  too,  an  opportunity  is  afforded  for  dis- 
guising poor  forms  of  the  constituents,  particularly 
nitrogen.  That  is,  in  a  mixture  of  nitrogenous 
materials,  potash  salts  and  superphosphates,  it  would 
be  a  difficult  matter  to  determine,  by  mere  physical 
inspection,  the  proportion  of  the  nitrogen  which  had 
been  supplied  in  the  form  of  horn  meal  and  of  blood, 
and  the  statement  of  the  manufacturer  on  this  point 
would  be  valuable  in  proportion  to  his  reliability. 
The  fact  that  in  mixtures  it  is  impossible  for  the  con- 
sumer to  distinguish  or  determine  the  proportions, 
amounts  or  kinds  of  the  constituents  is  so  fully  rec- 
ognized that  it  has  resulted  in  the  enactment  of  laws 
in  most  states,  which  require  that  manufacturers  or 
dealers  in  fertilizers  shall  state  the  actual  amounts  of 
the  different  constituents  contained  in  their  products, 
as  well  as  the  sources  from  which  they  were  derived, 
and  which  fix  a  penalty  for  any  failure  to  comply  with 
the  law  in  this  respect.  A  chemical  control  is  in  these 
cases  provided  for,  and  it  has  been  of  great  service 
both  to  the  good  manufacturers,  because  it  tends  to 
reduce  the  number  of  low-grade  brands  which  would 
naturally  come  into  competition  with  them  without 
such  protection,  and  to  the  consumers,  because  it 
protects  them  from  fraudulent  products. 

Laws  Alone   do  not  Fully   Protect 

Laws    alone,    however,    are   not   sufficient   to   fully 
protect  the  farmer  in  this  respect.     He  must  possess. 


I 


PURCHASE   OF  FEBTILIZEBS  131 

in  addition,  a  knowledge  of  what  constitutes  a  good 
fertilizer,  and  must  be  able  to  determine  from  the 
analysis  whether  there  is  a  proper  relation  between 
the  guarantee  and  the  selling  price,  and  whether  the 
materials  that  have  been  used  are  of  good  quality. 
The  fact  that  there  is  a  very  decided  lack  of  the  right 
sort  of  intelligence  on  this  point,  is  shown  by  the 
results  of  the  work  of  the  different  fertilizer  control 
stations.  These  demonstrate  clearly  that  farmers  do, 
in  many  cases,  pay  exorbitant  prices  for  their  fer- 
tilizer constituents,  not  because  the  manufacturer  did 
not  sell  what  he  claimed  to  sell,  but  because  the 
price  charged  by  the  dealer  was  far  in  excess  of  that 
warranted  by  the  guarantee.  For  example,  it  has 
been  repeatedly  shown  that  of  two  farmers  in  the 
same  neighborhood,  the  one  who  studies  the  matter 
and  understands  the  relation  of  guarantee  to  selling 
price,  may  pay  15  cents  per  pound  for  his  nitrogen, 
while  the  other,  who  does  not  study  the  matter,  buys 
on  the  ton  basis,  and  does  not  know  that  there  should 
be  such  a  relation  between  the  two,  may  pay  30 
cents  per  pound  for  the  same  quality  of  the  same 
constituent.  This  may  be  illustrated  by  the  follow- 
ing examples: 

Two  brands  are  offered,  made  up  from  the  same 
kind  and  quality  of  materials.  No.  1  is  guaranteed 
to  contain: 

Nitrogen \% 

Phosphoric  acid  (available) 6% 

Potash 1  % 


132  FERTILIZERS 

and  sells  for  $20  per  ton;  and  No.  2  is  guaranteed  to 
contain : 

Nitrogen 4  % 

Phosphoric  acid  (available) 8  % 

Potash     1% 

and  sells  for  $22  per  ton.  The  farmer  who  buys  on 
the  ton  basis,  or  is  guided  only  by  the  ton  price,  will 
be  induced  to  purchase  the  No.  1  brand,  because  by 
so  doing  he  apparently  saves  $2  per  ton.  The  one 
who  studies  the  relation  of  guarantee  to  selling  price 
will  purchase  the  No.  2  brand,  because  he  finds,  from 
a  simple  calculation,  that  it  furnishes  the  constituents 
at  just  one -half  the  cost  per  pound  of  the  No.  1 
brand,  notwithstanding  the  higher  ton  price,  which 
is  shown  by  the  following  calculation: 

No.  1 

Jjbs.       Cts. 
per  ton    per  lb. 

Nitrogen 1%  X  20  =    20  @  30  =  $6  00 

Phosphoric  acid  (available)  6%  X  20  =  120  @  10  =  12  00 

Potash 1%  X  20  =    20  @  10  =    2  00 

$20  00 

No.  2 

Lbs.        Cts. 
per  ton    per  lb. 

Nitrogen 4%  X  20  =    80  @  15  =  $12  00 

Phosphoric  acid  ( available )8%  X  20  =  160  @    5  =      8  00 

Potash 2%  X  20  =    40  (g,    5  =      2  00 

$22  00 
In  reality,  the   fertilizer  at  $22  per  ton  is  cheaper 
than  the  one  at  $20  per  ton. 


STATEMENT    OF    6UABANTEB  133 

Cost  per  pound  of  constituents  in: 

No.  1  No.  3 

Nitrogen $0  30  $0  15 

Phosphoric  acid  (available) 10  05 

Potash .        10  05 

This  may  seem  an  extreme  case,  but  it  is  well 
within  the  facts,  which  may  be  ascertained  by  con- 
sulting the  bulletins  on  fertilizer  analyses,  as  pub- 
lished by  the  different  states. 

Method   of  Statement   of  Guarantee  Sometimes 
Misleading 

Guarantees,  too,  are  sometimes  rendered  con- 
fusing to  the  purchaser,  because  of  the  method  of 
their  statement,  though  the  different  methods  used 
are,  in  one  sense,  entirely  legitimate,  because  the 
terms  used  are  in  accordance  with  the  facts.  From 
a  chemical  standpoint,  at  any  rate,  it  is  quite  as 
legitimate  to  guarantee  the  percentage  of  phosphoric 
acid  equivalent  to  bone  phosphate  of  lime,  as  it  is  to 
guarantee  the  percentage  of  actual  phosphoric  acid. 
It  is  because  the  consumer  believes  that  the  "equiva- 
lent" in  combination  means  that  he  is  obtaining  some- 
thing more  than  when  actual  constituents  only  are 
guaranteed,  that  he  is  led  to  purchase  more  freely, 
or  to  pay  a  higher  price.  Nitrogen  may  be  properly 
stated  in  its  equivalent  of  ammonia,  phosphoric  acid 
in  its  equivalent  of  bone  phosphate,  and  potash  in 
its  equivalent  of  muriate  of  potash,  and  it  is  the 
business  of  the  purchaser  to  understand  the  relations 
of   the   two   methods   of   statement,   in   order   that   he 


134 


FERTILIZERS 


may  not  be  misled  in  his  purchases.  The  following 
table  shows  the  terms  used,  their  equivalents,  and 
the  factor  to  use  in  multiplying,  in  order  to  convert 
the  one  into  the  other: 


To  convert  the  guarantee  of 
Ammonia  .... 
Nitrogen  .... 
Nitrate  of  soda  . 
Bone  phosphate  . 
Phosphoric  acid  . 
Muriate  of  potash 
Actual  potash  .  . 
Sulfate  of  potash 
Actual  potash  .    . 


into  an 

equivalent 

of 


Multiply  by 

Nitrogen 0.8235 

Ammonia 1.214 

Nitrogen 0.1647 

Phosphoric  acid  .  .  .  0.458 
Bone  phosphate  .  .  .  2.183 
Actual  potash  .  .  .  .0.633 
Muriate  of  potash  .  .  1.583 
Actual  potash  .  .  .  .0.54 
Sulfate  of  potash  .  .    .1.85 


Discussion   of  Guarantees 

It  is  shown  in  this  table  that,  in  order  to  convert 
ammonia  into  its  equivalent  of  nitrogen,  the  percent- 
age of  ammonia  should  be  multiplied  by  82  per  cent, 
or  divided  by  the  factor  1.214,  because  ammonia  is 
82  per  cent  nitrogen,  and  because  one  part  of  the 
nitrogen  is  equivalent  to  1.214  parts  of  ammonia. 

In  order  to  determine  the  cost  per  pound  of  nitro- 
gen in  dried  blood,  which  is  quoted,  for  example,  at 
$2  per  "unit," — 20  pounds  of  ammonia, — the  unit  20 
pounds  is  multiplied  by  82  per  cent,  which  gives 
16.40  as  the  pounds  of  nitrogen  offered  for  $2,  or 
12.14  cents  per  pound. 

Bone  phosphate  of  lime  is,  in  round  numbers,  46 
per  cent  actual  phosphoric  acid.  Hence,  by  multi- 
plying  the   bone   phosphate   by  46   per  cent,  the  per 


METHODS    OF     GUABAIfTUUJjVG  135 

cent  of  actual  phosphoric  acid  is  obtained.  Ground 
bone,  for  example,  guaranteed  to  contain  from  48  to 
52  per  cent  bone  phosphate,  contains,  in  round  num- 
bers, 22  to  24  per  cent  of  phosphoric  acid.  Sulfate 
of  potash  is  54  per  cent,  and  muriate  of  potash  is 
63  per  cent  "actual"  or  potassium  oxide,  respectively. 
Hence,  to  convert  the  percentages  of  these  forms 
into  their  equivalents  of  "actual,"  they  are  multiplied 
by  the  factors  given. 

In  such  raw  materials  as  nitrate  of  soda,  muriate 
of  potash,  and  sulfate  of  potash,  a  method  of  guar- 
anteeing is  used  which  is  based  upon  their  purity  as 
chemical  salts.  That  is,  when  pure  they  contain  100 
per  cent  of  the  specific  salt,  and  the  guarantee  accom- 
panying the  commercial  product  is  simply  a  statement 
indicating  their  purity.  For  example,  when  nitrate  of 
soda  is  guaranteed  to  contain  from  95  to  97  per  cent 
pure  nitrate,  it  means  that  it  is  95  to  97  per  cent 
pure,  or  that  3  to  5  per  cent  of  the  substance  consists 
of  impurities  ;  it  is  not  absolutely  pure  nitrate  of 
soda.  Hence,  the  minimum  percentage  of  nitrogen 
guaranteed  is  15.65  per  cent,  or  95  per  cent  of  16.47, 
the  per  cent  or  pounds  per  hundred  of  nitrogen  con- 
tained in  pure  nitrate  of  soda.  When  muriate  of 
potash  is  guaranteed  80  per  cent  muriate,  it  means 
that  80  per  cent  of  the  salt  consists  of  pure  muriate 
of  potash,  and  because  pure  muriate  of  potash  con- 
tains 63  per  cent  of  actual  potash,  or  potassium  oxide, 
the  actual  content  of  potash  is  derived  by  multiply- 
ing the  63  per  cent,  which  the  pure  salt  contains,  by 
80  per  cent,  and  the  result,   50.5  per  cent,  represents 


136  FERTILIZERS 

the  amount  of  actual  potash  guaranteed.  Sulfate  of 
potash,  high-grade,  is  usually  guaranteed  to  be  98 
per  cent  pure,  and  since  pure  sulfate  of  potash  con- 
tains 54  per  cent  of  actual  potash,  the  content 
of  actual  potash,  or  potassium  oxide,  guaranteed  is 
found  by  multiplying  the  54  per  cent  by  98  per  cent. 
The  following  illustrations  show  the  two  methods  of 
stating  the  guarantees  of  raw  materials  and  of  mixed 
fertilizers  : 

Raw   Materials 

Guarantee   on   Basis   op   Purity 

Nitrate  of  soda 98  %,  or  containing  98  %  pure  nitrate 

Muriate  of  potash    .    .    .    .  80  %,  "  "  80%     "      muriate 

Sulfate  of  potash 98  %,  "  "  98%     "     sulfate 

Kainit 25  %,  "  "  25  %     "     sulfate 

Guarantee   on   Basis  op  Actual   Constituents 

Nitrate  of  soda,  total  nitrogen 16.00  % 

Muriate  of  potash,  actual  potash - .    .    .  50.50  ft 

Sulfate  of  potash,  actual  potash 53.00  % 

Mixed   Fertilizers 
Guarantee  on  Basis  op  Equivalents  in  Combination 

Nitrogen  (equivalent  to  ammonia) 3  to    4  % 

Available  phosphoric  acid  (equivalent  to  bone  phos- 
phate of  lime) 18  to  22  % 

Potash  (equivalent  to  sulfate  of  potash) 10  to  12% 

Guarantee  on  Basis  op  Actual  Constituents 

Nitrogen  (total) 2.50  to    3.25  % 

Phosphoric  acid  (available) 8.00  to  10.00  % 

Potash  (actual) 5.50  to     6.50  % 


INTERPRETATION   OF    GUARANTEES  137 

The  guarantees  of  the  raw  materials  mean  prac- 
tically the  same  in  the  first  as  in  the  second  case.  In 
the  first,  the  percentages  given  indicate  the  purity  of 
the  chemical  salt ;  while  in  the  second,  the  figures 
given  indicate  the  actual  content  of  the  constituent 
contained  in  the  chemical  salt.  In  large  commercial 
transactions,  the  sales  are  frequently  made  on  the 
basis  of  certain  purity  percentages ;  as,  for  example, 
muriate  of  potash  is  sold  at  so  much  per  ton  on  the 
basis  of  80  per  cent  muriate.  If  the  analysis  shows 
it  to  contain  less  than  80  per  cent,  then  the  price 
paid  per  ton  is  less  in  proportion  to  such  deficiency. 
If  it  is  shown  to  contain  more  than  80  per  cent,  the 
purchaser  pays  for  the  excess  at  the  same  rate.  In 
round  numbers,  a  ton  of  muriate  on  the  80  per  cent 
basis  contains  1,000  pounds  of  actual  potash;  if  the 
price  is  $40  per  ton,  the  cost  per  pound  is  4  cents. 
If  analysis  shows  but  900  pounds  instead  of  1,000, 
the  price  paid  per  ton,  at  4  cents  per  pound,  is  $36. 
If,  on  the  other  hand,  it  is  shown  to  contain  1,100 
pounds,  the  price  paid  per  ton  is  $44.  Purchase 
made  when  this  method  of  guaranteeing  is  used  is 
practically  equivalent  to  the  "unit"  basis,  though,  as 
already  stated,  unless  it  is  thoroughly  understood,  it 
is  likely  to  be  misleading. 

What  has  been  said  of  the  different  statements 
of  guarantees  of  the  raw  materials,  is  also  true  in 
the  case  of  the  mixed  goods.  In  the  first,  the  per- 
centages of  the  elements  that  are  given  represent  the 
amounts  when  they  exist  in  combination  with  other 
elements :    nitrogen,    as    ammonia ;     phosphoric    acid, 


138  FERTILIZERS 

as  bone  phosphate,  and  potash,  as  sulfate.  While 
in  the  other,  the  percentages  given  indicate  the  con- 
tent of  the  actual  constituents  :  namely,  nitrogen, 
phosphoric  acid  and  potash. 

The  Advantages  and  Disadvantages  of  Purchasing  Raw 
Materials  and  Mixed  Fertilizers 

In  the  purchase  of  fertilizers,  therefore,  two  meth- 
ods may  be  adopted  :  First,  the  buying  of  fertiliz- 
ing materials,  as  distinct  from  fertilizers,  which  fur- 
nish single  constituents  like  the  standard  high-grade 
products,  or  which  furnish  one  or  two  of  the  con- 
stituents, like  ground  bone,  tankage,  fish,  and  the  mis- 
cellaneous products;  these  are  called  "incomplete," 
because  they  do  not  furnish  all  of  the  three  essential 
constituents.  Second,  the  purchase  of  the  mixed 
manufactured  brands,  which  contain  all  of  the  three 
essential  constituents,  nitrogen,  phosphoric  acid,  and 
potash,  which  are  prepared  to  meet  the  demands  of 
different  soils  and  crops,  and  are  called  "complete," 
because  containing  all  of  the  essential  manurial  con- 
stituents, or  those  liable  to  be  lacking  in  any  soU. 
The  relative  advantage  of  these  different  methods 
of  purchase  depends,  first,  upon  the  cost  of  the  con- 
stituents, and  second,  upon  the  use  that  is  to  be 
made  of  them. 

It  may  be  urged  that,  on  theoretical  grounds,  there 
are  no  good  reasons  why  nitrate  of  soda,  sulfate  of 
ammonia,  dried  blood,  superphosphates  and  potash 
compounds   should   be   mixed,  as   the   manufacture   of 


DIFFERENT  METHODS   OF  PURCHASE  139 

these  does  not  improve  or  change  the  quality  of  the 
constituents — it  consists  chiefly  in  simply  grinding, 
mixing  and  bagging.  There  are,  however,  advan- 
tages and  disadvantages  in  both  methods  of  purchase, 
the  chief  of  which  are  stated  below. 

The  advantages  in  the  purchase  and  use  of  raw 
materials  are  :* 

1.  A  better  knowledge  of  the  kind  and  quality 
of  plant -food  obtained.  That  is,  these  products 
as  a  rule  possess  characteristics  which  distinguish 
them  from  others  and  from  each  other,  and  they 
are  more  likely  to  be  uniform  in  composition  than 
mixtures. 

2.  It  enables  the  use  of  one  or  more  of  the  con- 
stituents as  may  be  found  necessary,  thus  avoiding 
the  expense  of  purchasing  and  applying  those  not 
required  for  the  particular  crop  or  soil.  The  farmer 
is  also  enabled  to  adjust  the  forms  and  proportions 
of  the  various  ingredients  to  suit  what  he  has  found 
to  answer  the  needs  of  his  soil  or  crop. 

3.  A  saving  in  the  cost  of  plant -food,  since  in 
their  concentrated  form,  the  expenses  of  handling, 
mixing  and  rebagging  are  avoided. 

The  chief  disadvantages  are  : 

1.  The  materials  are  not  generally  distributed 
among  dealers,  and  thus  not  so  readily  obtained. 

2.  It  is  difficult  to  spread  evenly  and  thinly  pro- 
ducts of  so  concentrated  a  character,  particularly  the 
chemical  salts,  which,  unless  great  care  is  used,  may 


♦"First  Principles  of  Agriculture." 


140  FERTILIZERS 

injure  by  coining  in  immediate  contact  with  the  roots 
of  plants. 

3.  The  mechanical  condition  or  degree  of  fineness 
is  less  perfect  than  in  the  manufactured  products. 

The  advantages  in  the  purchase  and  use  of  com- 
plete manures  are  : 

1.  They  are  generally  distributed,  and  can  be  pur- 
chased in  such  amounts  and  at  such  times  as  are  con- 
venient. 

2.  The  different  materials  may  be  well  propor- 
tioned, both  as  to  form  of  the  constituents  and  their 
relative  amount  for  the  various  crops. 

3.  The  products  are,  as  a  rule,  finely  ground  and 
well -prepared  for  immediate  use. 

The  chief  disadvantages  are  : 

1,  That  it  is  impossible  to  detect  in  a  mixture 
whether  the  materials  are  what  they  are  claimed  to  be. 

2.  That  without  a  true  knowledge  of  what  consti- 
tutes value,  many  are  led  to  purchase  on  the  ton  basis, 
without  regard  to  the  quantity  and  quality  of  the 
plant -food  offered. 

There  is  no  question  that  the  actual  cost  of 
the ,  constituent  is  less  when  purchased  in  the  fertiliz- 
ing material  than  in  the  manufactured  brand,  as  not 
only  the  expenses  of  mixing  and  bagging  are  saved, 
but  the  cost  of  handling  the  product  per  unit  of 
plant -food  is  much  less  in  the  highly  concentrated 
materials  than  in  mixtures  made  up  of  both  classes 
of  fertilizing  materials. 

In  the  purchase  of  fertilizers  by  the  second  method, 
the  cost  of  the  constituents  is  not  only  higher  on  the 


HOME    MIXING  141 

average,  but  the  variations  in  their  cost  are  very- 
much  greater,  due  to  the  differences  in  the  charges 
made  by  the  different  manufacturers  for  handling  and 
selling  their  products. 

HOME    MIXTURES 

The  fact  that  fertilizing  materials  are  a  regular 
article  of  trade,  and  may  be  purchased  as  such,  and 
the  fact  that  a  complete  fertilizer,  so-called,  is  really 
only  a  mixture  of  the  various  manufactured  fertilizing 
materials,  has  suggested  the  use  of  what  are  called 
"home  mixtures," — that  is,  their  mixing  by  the 
farmer  himself.  This  has  proved  to  be  very  satisfac- 
tory under  proper  conditions,  since,  as  already  stated, 
,the  cost  of  the  constituents  is  much  less  than  if 
secured  in  the  average  manufactured  brand  (often 
from  25  to  50  per  cent),  and  the  mixing  can  be  per- 
formed by  the  regular  labor  of  the  farm,  and  thus 
not  add  directly  to  the  cost  of  the  constituent. 

This  matter  of  home  mixtures  has  been  carefully 
studied  by  a  number  of  the  experiment  stations, 
notably  Connecticut,  Rhode  Island  and  New  Jersey. 
The  results  of  their  studies  are  published  in  their 
regular  reports,  and  show  that  the  materials  can  be 
evenly  mixed  on  the  farm,  that  the  mechanical  con- 
dition is  good,  and  that  the  results  obtained  from 
their  use  are  entirely  satisfactory.  It  must  be  remem- 
bered, however,  that  whatever  method  of  purchase  is 
used,  the  object  should  be  to  obtain  the  kind  and 
form    of    constituent    best    suited    to    the    conditions 


142  FERTILIZERS 

under  which  they  shall  be  used,   at  the  lowest  price 
per  pound. 

In  any  method  of  purchase  which  contemplates 
the  use  of  a  mixture,  care  should  be  taken  in  the 
selection  of  the  brand  or  of  the  formula,  since  in 
mixtures  as  well  as  in  the  raw  materials,  there  are 
two  grades,  the  high-grade  and  the  low-grade — 
high-grade  in  the  sense  that  in  quality  the  con- 
stituents are  all  good,  and  in  the  sense  that  maxi- 
mum quantities  are  contained;  and  second,  high- 
grade  only  in  that  constituents  of  good  quality 
are  furnished.  They  may  be  low-grade  in  the  sense 
that  both  the  quality  and  amount  of  constituents 
contained  are  low,  and  also  in  the  sense  that  only 
the  quality  of  the  constituents  is  low,  the  quan- 
tity being  sufficiently  high.  , 

Formulas 

The  following  formulas  are  used  for  the  sole  pur- 
pose of  illustrating  the  differences  that  may  exist 
between  high-grade  and  low-grade  mixtures,  and  not 
as  indicating  what  should  be  used  to  make  a  good 
or  poor  mixture  : 

Formula  No.   1 

Nitrate  of  soda  .    .     500  lbs.  furnishing    80  lbs.  nitrogen 
High-grade  super- 
phosphate    .    .  1,100    "  "         180    "    phos.  acid  avail. 
Muriate  of  potash,      400    "  "  200    "     potash 

Total 2,000    "  "         460    "    total  plant-food 


FORMULAS  143 

With  a  guaranteed  composition  of  : 

Nitrogen 4  % 

Phosphoric  acid  (available) 9  % 

Potash 10  % 

Formula  No.   2 

Nitrate  of  soda.  .    .     250  lbs.  furnishing    40  lbs.  nitrogen 
High-grade  super- 
phosphate    ..  1,000    "  "  160    "     phos.  acid  avail. 
Muriate  of  potash,        80    "            "  40    "     potash 
Make -weight  ...     670    "            " 

Total 2,000    "  "  240    "     total  plant-food 

With  a  guaranteed  composition  of : 

Nitrogen 2  % 

Phosphoric  acid  (available) 8  % 

Potash • 2  % 

FOKMTJLA    No.     3 

„  ^„„  ,,      „       .  ,  .       r  30  lbs.  nitrogen 

T^^^^g« eOOlbs.fumishingjg^    ..    phosphoric  acid 

Kainit 400    "  "  50    "    potash  (actual) 

Make-weight  .   .   .  1,000    " 

Total 2,000    "  "  170    "    total  plant -food 

With  a  guaranteed  composition  of : 

Nitrogen 1.5  % 

Phosphoric  acid 4.5  % 

Potash  (actual) 2.5  % 

Formula  No.  4 
^  .  ^„«  „       -       .  ,  .      r  60  lbs.  nitrogen 

T^^k^g« 1'200  lbs.  furnishingj^g^    „    phosphoric  acid 

Kainit 800    "  "  100    "    potash  (actual) 


Total 2,000    '*  "  340    "    total  plant-food 


144  FERTILIZERS 

With  a  guaranteed  composition  of : 

Nitrogen 2% 

Phosphoric  acid 9  % 

Potash b% 

Formula  No.  1  shows  a  high-grade  product,  both 
in  respect  to  quality  of  plant -food  and  concentration, 
while  No.  2  is  high-grade  only  in  respect  to  quality. 
In  order  that  the  plant -food  may  be  distributed 
throughout  a  ton  of  material,  it  is  necessary  to  add 
what  is  called  "make -weight,"  or  a  diluent.  These  usu- 
ally consist  of  substances  that  possess  no  direct  fer- 
tilizing value.  High-grade  mixtures  cannot  be  made 
from  low-grade  materials,  and  low-grade  mixtures 
cannot  be  made  from  high-grade  materials  without 
adding  "make -weight."  The  advantages  of  high- 
grade  products  are  concentration  and  high  quality 
of   plant -food. 

It  will  be  observed  that  formula  No.  1  contains 
nearly  twice  as  much  plant -food  as  No.  2,  or,  in 
other  words,  it  will  require  about  two  tons  of  a  fer- 
tilizer made  according  to  formula  No.  2  to  secure  the 
same  total  amount  of  plant -food  as  is  contained  in 
one  ton  of  No.  1.  Now,  the  material  in  No.  2,  other 
than  the  actual  plant-food,  is  of  no  direct  ferti- 
lizing value, — it  is  of  no  more  value  as  a  fertilizer 
than  the  soil  to  which  it  is  applied, — but  the 
actual  cost  of  the  constituents  is  considerably  in- 
creased, because  the  expenses  of  handling,  bagging 
and  shipping  are  just  double  what  they  would  be 
for  No.  1. 


DISCUSSION    OF   FORMULAS  145 

Formula  No.  3  illustrates  a  low-grade  fertilizer  in 
the  sense  that  it  contains  the  poorer  forms  of  the  con- 
stituents, and  furnishes  a  comparatively  small  total 
amount  of  plant -food.  The  nitrogen  is  all  in  the 
organic  form,  and  is  derived  from  tankage,  which, 
while  not  the  poorest,  is  poorer  than  other  forms  of 
organic  nitrogen.  The  phosphoric  acid  is  also  in 
organic  combination,  and,  while  useful  under  many 
conditions,  is  less  useful  for  certain  other  conditions 
than  the  soluble  in  Nos.  1  and  2.  The  potash,  while 
soluble,  is  derived  from  kainit,  which,  because  of  its 
large  content  of  chlorin,  is  regarded  as  less  desirable 
for  certain  crops  than  the  more  concentrated  materials, 
muriate,  or  the  high-grade  sulfate,  which  is  free  from 
chlorids.  It  would  require  more  than  2%  tons  of  a 
mixture  made  according  to  this  formula  to  furnish  as 
much  total  plant -food  as  would  be  contained  in  a 
mixture  made  according  to  formula  No.  1,  besides  the 
disadvantage  of  the  lower  quality  of  the  constituents. 

Formula  No.  4  illustrates  a  mixture  which,  while 
rich  in  total  constituents,  is  not  high-grade  in  its 
quality. 

All  of  these  considerations  should,  therefore,  be 
carefully  observed  in  the  purchase  of  mixtures,  or  even 
in  the  purchase  of  raw  materials  for  home  mixtures, 
and  the  analysis,  if  properly  made,  will  give  positive 
evidence  on  these  points. 

The  expensiveness  of  low-grade  fertilizers,  as  repre- 
sented by  formulas  Nos.  2  and  3,  is  not  fully  appre- 
ciated by  the  purchaser  in  all  cases.  He  does  not  stop 
to  think  that   it   is  quite  as  expensive  to   handle   the 


146  FERTILIZERS 

material   which    contains    no   plant -food    as    it    is    to 
handle  material  which  is  rich  in  plant -food. 

The   Cost  of  Handling  ^^  Make -weight" 

A  comparison  of  the  advantages  of  low-grade  and 
high-grade  mixtures  in  this  sense  of  total  quantity  of 
plant -food  may  be  illustrated  as  follows  : 

It  has  been  shown  by  continued  studies  at  the  New 
Jersey  Experiment  Station  that  the  charges  of  the 
manufacturers  and  dealers  for  mixing,  bagging,  ship- 
ping and  other  expenses  are,  on  the  average,  $8.50  per 
ton  ;  and  also  that  the  average  manufactured  fertilizer 
contains  about  three  hundred  pounds  of  actual  fer- 
tilizing constituents  per  ton.  A  careful  study  of  the 
fertilizer  trade  indicates  that  these  conditions  are  also 
practically  true  for  other  states  in  which  large  quanti- 
ties of  commercial  fertilizei's  are  used. 

A  mixture  of  formula  No.  1  would  contain  460 
pounds  of  actual  available  fertilizing  constituents  per 
ton — 160  pounds,  or  over  50  per  cent  more  than  is 
contained  in  the  average  manufactured  brand.  That 
is,  a  farmer  purchasing  a  brand  similar  to  formula 
No.  1  would  secure  in  2  tons  as  much  plant -food 
as  would  be  contained  in  3  tons  of  the  average  man- 
ufactured brand.  Assuming  that  the  charges  per 
pound  of  plant -food  at  the  factory,  and  the  expense 
charges,  are  the  same  in  each  case,  and  also  that  the 
quality  of  plant -food  in  the  one  is  as  good  as  in  the 
other,  the  consumer  would  save  $8.50  by  purchasing 
two  tons  of   the  former   instead  of    three  tons  of  the 


CONCJENTRATED    FEBTILIZEBS  147 

latter.  In  a  few  states  the  consumption  of  fertilizers 
reaches  nearly  100,000  tons  annually,  while  in  many 
it  ranges  from  30,000  to  50,000  tons. 

Thus  is  shown  the  very  great  saving  that  may  be 
effected  in  the  matter  of  the  purchase  of  fertilizers 
from  the  standpoint  of  concentration  alone,  or,  in 
other  words,  the  importance  of  a  definite  knowledge 
of  what  constitutes  value  in  a  fertilizer.  This  saving 
may  be  accomplished,  too,  without  any  detriment  to 
the  manufacturer,  since  the  difference  to  him  between 
making  high-grade  or  low-grade  goods,  in  reference 
to  concentration,  is  largely  a  matter  of  unskilled  labor. 
The  manufacturers  are  in  the  business  to  cater  to  the 
demands  of  the  trade.  If  consumers  are  intelligent, 
high-grade  rather  than  low-grade  goods  will  be  pro- 
vided by  the  manufacturers.  Furthermore,  as  already 
indicated,  high-grade  in  the  matter  of  concentration 
means  high-grade  in  quality,  for  high-grade  mixtures 
cannot  be  made  from  low-grade  products. 

GENERAL    ADVICE 

As  farmers  understand  more  fully  the  question  of 
fertilization,  and  as  intensive  methods  of  practice  are 
adopted,  the  tendency  in  the  purchase  of  fertilizers 
will  undoubtedly  be  toward  the  first  method,  or  the 
purchase  of  fertilizing  materials,  rather  than  mixtures, 
or  at  any  rate,  of  high-grade  special  mixtures,  rather 
than  what  are  now  termed  "standard  brands,"  which 
are,  as  a  rule,  low-grade  in  the  concentrated  sense. 
This  tendency  will  come,  first,  because  intensive  prac- 


148  FERTILIZERS 

tice  requires  a  larger  use  of  all  of  the  constituents, 
and  second,  a  greater  need  in  the  growth  of  certain 
crops  of  specific  or  dominant  elements,  and  thus  better 
results  are  obtained  from  the  application  of  single 
constituents,  or  the  use  of  special  formulas,  than  in 
"extensive"  practice,  in  which  the  object  is  more  to 
supplement  the  soil  supplies  than  to  fully  provide 
for  all  the  needs  of  the  plants  for  food. 

The  tendency  toward  cooperative  buying  on  the 
part  of  small  farmers  will  increase  as  it  has  done  in 
those  countries  in  which  there  is  a  larger  use  of 
fertilizers  than  here,  though  the  method  is  already  in 
successful  operation  in  certain  sections  of  the  country, 
and  with  very  gratifying  results.  In  this  method  of 
direct  purchase,  the  manufacturer  and  the  consumer 
are  brought  into  closer  relations  with  each  other. 
Transactions  are  based  upon  the  transfer  of  a  definite 
number  of  pounds  of  a  specific  kind  and  form  of 
plant-food,  rather  than  upon  some  mysteriously  re- 
markable qualities  that  are  claimed,  and  are  by  many 
supposed  to  be  inherent  in  certain  mixtures. 


CHAPTER  VIII 

CHEMICAL   ANALYSES   OF  FERTILIZERS 

A  COMPLETE  chemical  analysis  of  a  fertilizer  shows 
not  only  the  total  amount  of  the  different  constituents 
contained  in  a  brand,  but  the  form  in  which  they 
exist,  and  in  most  cases,  the  source  of  the  materials 
used  is  also  indicated. 

THE   INTERPRETATION   OF   AN  ANALYSIS 

An  analysis  may  show  simply  the  total  amount  of 
the  constituents.  This  is  not  a  sufficient  guide  as  to 
the  value  of  a  mixture,  for  while  it  is  not  possible  to 
indicate  absolutely  by  analysis  whether  the  organic 
nitrogen,  for  example,  is  derived  from  blood  (which  is 
one  of  the  best  forms),  or  from  horn  meal  (one  of  the 
poorer  forms) ,  it  is  possible  to  show  whether  the  nitro- 
gen is  derived  from  nitrate  or  from  ammonia,  whether 
the  phosphoric  acid  is  derived  from  a  superphosphate 
or  a  phosphate,  and  whether  the  potash  present  is  in 
the  form  of  a  sulfate  or  of  a  muriate.  A  high-grade 
or  a  low-grade  fertilizer,  for  example,  may  be  distinctly 
indicated  by  the  analysis,  since  it  is  of  a  high-grade 
if  the  three  forms  of  nitrogen  are  present,  if  the  total 
phosphoric  acid  is  chiefly  soluble  in  water,  and  if  the 
potash    has   been    derived    from  a  sulfate   or  from  a 

(149) 


150  FERTILIZERS 

muriate.  On  the  other  hand,  if  the  analysis  shows 
that  the  nitrogen  is  all  in  the  organic  form,  that  only 
a  minimum  percentage  of  the  phosphoric  acid  is 
available,  though  not  soluble,  and  that  a  high  con- 
tent of  chlorin  accompanies  the  potash,  it  is  a  low- 
grade  product,  in  so  far  as  the  form  of  the  constituents 
is  concerned.  The  following  statements  of  analyses 
of  two  brands,  showing  the  same  total  content  of 
constituents,  illustrate  this  point: 

Analysis  No.  1 

Nitrogen,  as  nitrate 1% 

"  "   ammonia 1% 

"  "   organic  matter 1% 

Total 3% 

Phosphoric  acid,  soluble 8% 

"  "     reverted 1% 

"  "     insoluble 1% 

Total  available 9% 

Potash 5  % 

Chlorin 0.50  % 

Analysis  No.  2 

Nitrogen,  as  nitrate 

"         "    ammonia 

"         "    organic  matter 3  % 

Total 3% 

Phosphoric  acid,  soluble 

'•  "       reverted 2% 

'■  "       insoluble 8% 

Total  available 2  % 

Potash 5% 

Chlorin 10% 

A  study  of  these  two  statements  of  analyses  shows 
that  the  total  contents  of  the  constituents  are  identical, 


VALUE    OF  A    CHEMICAL  ANALYSIS  151 

3,  10  and  5,  respectively,  in  each  case.  That  is,  so 
far  as  the  total  amounts  are  concerned,  one  brand 
furnishes  as  much  as  the  other,  and  from  that  stand- 
point alone  it  is  as  good  as  the  other  ;  but  it  has  been 
already  shown  that  the  value  of  a  fertilizer  depends 
not  only  upon  the  total  content  of  its  constituents, 
but  upon  the  form  in  which  they  exist.  In  the  first 
brand  it  is  found  that  two -thirds  of  the  total  nitrogen 
exists  in  the  soluble  form,  equally  divided  between 
nitrate  and  ammonia;  the  remaining  third  is  in  the 
organic  form,  and  may  be  derived  from  blood,  or  from 
some  low-grade  materials.  It  is  to  be  fairly  presumed, 
however,  that  when  thus  associated  with  so  high  a 
proportion  of  soluble  nitrogen,  it  is  in  a  good  form,  as 
the  manufacturer  has  given  evidence  of  his  intent  by 
his  liberal  use  of  other  good  forms. 

In  the  case  of  the  phosphoric  acid,  it  is  shown 
that  of  every  100  pounds  of  the  total,  80  pounds  are 
soluble,  10  reverted,  or  nine -tenths  of  the  whole  is 
available  ;  10  pounds  of  every  hundred  only  are  in- 
soluble, which  is  not  only  an  indication,  but  positive 
proof,  that  the  phosphoric  acid  is  derived  from  a 
superphosphate. 

In  the  case  of  potash,  the  ehlorin  associated  with 
it  is  but  %  per  cent,  indicating  that  it  has  been  drawn 
from  high-grade  sulfate,  since  kainit  and  muriate 
are  rich  in  ehlorin,  while  in  a  high-grade  sulfate  no 
appreciable  amounts  of  ehlorin  are  present. 

In  the  second  statement,  all  of  the  nitrogen  is 
shown  to  be  in  the  form  of  organic  matter.  It  may 
be  derived  from  blood,  though  it  is  not  likely  to  have 


152  FERTILIZERS 

been  drawn  from  this  source,  since  of  tlie  total 
phosphoric  acid  but  20  pounds  per  hundred,  or  one- 
fifth,  is  available,  and  that  is  reverted  rather  than 
soluble,  indicating  that  the  phosphoric  acid  must  have 
been  drawn  from  tankage  or  from  bone,  or  other  ma- 
terials which  contain  reverted  but  no  soluble  phos- 
phoric acid,  and  which  also  contain  a  considerable 
percentage  of  nitrogen.  The  phosphoric  acid  was  cer- 
tainly not  drawn  from  a  superphosphate,  or  it  would 
have  shown  a  higher  percentage  of  available,  a  cer- 
tain proportion  of  which  would  have  been  soluble,  and 
the  percentage  of  insoluble  would  have  been  very  much 
less.  In  the  case  of  potash,  it  is  quite  evident  that 
it  was  drawn  from  kainit,  inasmuch  as  the  percentage 
of  chlorin  exceeds  the  percentage  of  the  potash,  as 
would  be  the  case  if  the  potash  had  been  drawn  from 
that  source. 

Thus  it  is  that  a  complete  chemical  analysis  of  a 
fertilizer  indicates  very  clearly  the  source  of  the 
materials  by  the  form  in  which  the  constituents  exist 
in  the  mixture. 

THE    AGRICULTURAL   VALUE   OF  A  FERTILIZER 

It  is  obvious,  from  what  has  already  been  pointed 
out,  that  the  value  of  a  fertilizer  to  the  farmer 
depends  not  so  much  upon  what  is  paid  for  it  as  upon 
the  character  of  the  materials  used  to  make  it.  This 
value  is  termed  the  "agricultural  value,"  and  it  is 
measured  by  the  value  of  the  increased  crop  produced 
by  its  use.     It  is,  therefore,  a  variable  factor,  depend- 


AGRICULTUBAL    VALUE  OF  A   FERTILIZER     153 

ing  first,  upon  the  availability  of  its  constituents,  and 
second,  upon  the  value  of  the  increased  crop  produced. 
For  example,  in  the  first  place,  the  agricultural 
value  of  a  pound  of  soluble  phosphoric  acid  is  likely 
to  be  greater  than  that  of  a  pound  of  insoluble  when 
applied  under  the  same  conditions  as  to  soil  and  crop, 
because  in  the  one  case  the  element  is  in  its  most 
available  form,  while  in  the  other  it  is  least  available. 
In  the  second  place,  the  soluble  phosphoric  acid  may 
exert  its  full  effect  and  cause  a  greatly  increased  yield 
on  a  certain  crop,  and  still  not  cause  an  increase  in  its 
value  sufficient  to  pay  the  cost  of  the  application, 
while  for  another  crop  the  same  application  may 
result  in  a  very  great  increase  in  the  value  of  the 
crop.  The  character  or  form  of  the  materials  used  in 
a  mixture,  as  well  as  their  suitability  for  the  crop 
must,  therefore,  be  carefully  considered  in  the  pur- 
chase of  fertilizers.  Slow -acting  materials  cannot  be 
expected  to  give  profitable  returns,  particularly  upon 
quick -growing  crops,  nor  expensive  materials  such 
profitable  returns,  when  used  for  crops  of  relatively 
low  value,  as  for  crops  of  relatively  high  value. 

THE    COMMERCIAL    VALUE    OF    A    FERTILIZER 

This  agricultural  value  is,  however,  separate  and 
distinct  from  what  is  termed  "commercial  value,"  or 
cost  in  market.  This  value  is  determined  by  market 
and  trade  conditions,  as  the  cost  of  production  of 
the  crude  materials  and  the  cost  of  their  manufacture 
and   sale.      Since   there   is  no  strict    relation   between 


154  FERTILIZERS 

agricultural  and  commercial  or  market  value  of  a  fer- 
terlizer  constituent,  it  frequently  happens  that  an 
element  in  its  most  available  form,  and  under  ordi- 
nary conditions  of  high  agricultural  value,  costs  less 
in  market  than  the  same  element  in  less  available 
forms  and  of  a  lower  agricultural  value.  The  cost  of 
production  in  the  one  case  is  lower  than  in  the  other, 
though  the  returns  in  the  field  are  far  superior. 

It  is  manifestly  impossible  to  fix  an  agricultural 
value  for  any  of  the  constituents  that  will  be  true 
under  the  varying  conditions  of  soil,  crop  and  season, 
and  method  of  use,  though  the  relative  value  of  the 
different  forms  under  uniform  conditions  of  use  may 
be  fairly  indicated,  and  the  analysis  is  the  guide  as 
to  their  form.  The  commercial  value  of  the  different 
constituents  in  their  various  forms  may,  too,  be  fairly 
indicated,  and  will  vary  according  to  variations  in 
trade  conditions.  If  the  wholesale  jobbing  price  of 
nitrogen  as  nitrate  is  15  cents  per  pound,  available 
phosphoric  acid  5  cents  per  pound,  and  potash  4  cents 
per  pound,  these  are  the  prices  which  the  manufacturers 
pay.  Their  increased  cost  in  manufactured  brands, 
therefore,  is  in  proportion  to  the  cost  of  this  work  ; 
hence  their  cost  to  the  consumer  at  factory  should 
vary  within  reasonably  narrow  limits,  due  to  varia- 
tions in  cost  of  manufacturing  in  different  localities. 

An  illustration  of  the  commercial  value  is  shown 
by  the  following  example :  Suppose  that  nitrate  of 
soda  costs  or  can  be  purchased  at  retail,  in  ton  lots, 
for  $48  per  ton,  which  is,  then,  its  commercial  value. 
The   commercial    or    trade  value   of    the   nitrogen   is, 


COMMEBCIAL    VALUE   OF  A   FERTILIZER        155 

therefore,  15  cents  per  pound,  since  a  ton  contains  on 
the  average  320  pounds  of  nitrogen.  Or,  suppose 
that  the  retail  price  of  available  phosphoric  acid  in 
superphosphates  is  $1  per  unit ;  this  is  its  commercial 
value,  and  hence  the  commercial  or  trade  value  of 
the  available  phosphoric  acid  would  be  5  cents  per 
pound,  since  a  unit  contains  20  pounds.  It  does 
not  follow  that  the  application  of  a  pound  of  nitrogen, 
costing  15  cents,  and,  therefore,  having  a  commercial 
value  of  15  cents,  will  result  in  an  increased  crop 
worth  15  cents,  or  that  the  application  of  a  pound  of 
phosphoric  acid  costing  5  cents  per  pound  will  result 
in  an  increased  crop  worth  5  cents.  The  increased 
returns .  in  crop  from  their  use  may  be  very  much 
greater  or  much  less  than  the  cost  of  the  constituents, 
depending  upon  the  kind  of  crop  and  the  skill  of  the 
user.  In  the  purchase  of  materials,  however,  a  com- 
mercial valuation  is  a  guide  as  to  the  cost  of  the  con- 
stituents from  different  manufacturers  or  dealers ;  and 
in  many  states  a  system  of  commercial  values  for 
mixed  fertilizers  has  been  fixed,  which,  when  properly 
understood,  is  a  useful  method  of  comparison  of  the 
different  brands. 

This  method  is  based -upon  the  fact  that  at  points 
of  supply  a  pound  of  nitrogen,  in  the  form  of  nitrate, 
of  ammonia,  or  of  definite  organic  compounds,  or  a 
pound  of  available  phosphoric  acid,  or  of  potash  in 
the  form  of  muriate  or  sulfate,  is  practically  the  same 
to  all  manufacturers.  That  is,  these  cost  prices,  or 
trade  values,  when  applied  to  the  constituents  in  the 
mixture,  represent  their  commercial  value  before  they 


156  FERTILIZERS 

are  mixed  to  form  complete  fertilizers.  Hence,  the 
difference  between  the  valuation  of  a  brand  on  this 
basis  and  the  cost  to  the  consumer  represents  the 
charges,  including  profit,  for  mixing,  bagging,  ship- 
ping and  selling  the  goods. 

The  commercial  or  trade  value  for  each  of  these 
constituents  is  obtained,  as  already  indicated,  by 
simply  calculating  the  cost,  using  two  factors,  — 
the  wholesale  prices  for  the  different  materials  con- 
taining them,  and  their  average  composition.  To 
this  cost  is  added  a  certain  percentage,  to  represent 
the  cost  of  handling  and  distribution  in  small  lots. 
Thus  the  trade  value  corresponds  as  nearly  as  may 
be  with  the  cost  of  the  constituents  to  the  farmer. 
That  is,  the  price  fixed  represents  what  the  farmer 
would  have  to  pay  the  manufacturer  for  the  con- 
stituents in  the  material  before  it  is  mixed. 

For  example,  suppose  the  wholesale  price  per  ton 
of  nitrate  of  soda  for  the  six  months  preceding  March 
1  is  shown  to  be  $40  ;  the  wholesale  cost  of  nitrogen 
in  this  form  is,  therefore,  12.5  cents  per  pound.  To 
this  wholesale  price  may  be  added  a  certain  sum  to 
cover  the  expenses  of  handling,  usually  20  per  cent, 
thus  making  the  retail  price  per  ton  $48,  and  the 
trade  or  commercial  value  of  the  nitrogen  15  cents 
per  pound.  That  is,  the  $48  per  ton,  or  15  cents 
per  pound,  represents  the  retail  cost  per  pound  of 
nitrate  nitrogen.  This,  if  applied  to  the  nitrogen  as 
nitrate,  in  the  mixed  fertilizer,  will  show  what  it 
could  have  been  bought  for  as  nitrate  in  the  unmixed 
fertilizer.     The   values   for   the   other  constituents  are 


SCHEDULE    OF    TBADE    VALUES  157 

derived  in  the  same  way.  These,  together,  make  the 
schedule  of  trade  or  commercial  values  of  the  con- 
stituents which  are  used  in  the  computing  of  the 
commercial  values  of  mixed  fertilizers.  The  schedule 
of  values  is  revised  annually,  and,  as  nearly  as  pos- 
sible, at  the  same  time  in  the  year.  The  following 
schedule,  used  as  an  illustration  of  this  point,  was 
adopted  for  1898  by  the  states  of  New  York,  Con- 
necticut, Rhode  Island,  Massachusetts,  Vermont  and 
New  Jersey: 

Schedule  of  Trade  Values  Adopted  by  Experiment 
Stations  for  1898 

CU.  per  lb. 

Nitrogen,  as  nitrates 13.0 

"         "   ammonia  salts 14.0 

Organic  nitrogen,  in  dried  and  fine -ground  fish,  meat  and 

blood,  and  in  mixed  fertilizers 14.0 

Organic  nitrogen,  in  fine-ground  bone  and  tankage*  ....  13.5 

"  "  "  coarse  bone  and  tankage  t 10.0 

Phosphoric  acid,  soluble  in  water 4.5 

"  "  "        "  ammonium  citrate  t 4.0 

"  "      insoluble,  in  fine  bone  and  tankage*  .    .    .    4.0 

"  "  "  "   coarse  bone  and  tankaget  .    •    3.5 

"  "  "  "   mixed  fertilizers 2.0 

"  "  "  "   fine -ground   fish,  cotton -seed 

meal,  castor  pomace  and  wood  ashes 4.0 

Potash,  as  muriate 4.25 

"        "   sulfate,    and    in   forms   free    from  muriates   (or 
chlorids) 5.0 


*  Finer  than  1-50  inch. 

t  Coarser  than  1-50  inch. 

tin  New  Jersey,  the  price  for  the  soluble  and  reverted  is  identical;  viz., 
4.5  cents,  owing  to  the  different  method  used  in  the  determination  of  the 
"reverted." 


158  FEBTILIZEBS 

It  will  be  observed  that  the  schedule  gives  the 
cost  per  pound  of  the  different  forms  of  nitrogen, 
and  of  high-grade  organic  nitrogenous  materials  ;  of 
nitrogen  and  phosphoric  acid  in  ground  bone  and 
tankage ;  of  available  phosphoric  acid  in  superphos- 
phates, and  of  actual  potash  in  the  potash  salts,  and 
is  a  useful  guide  also  in  showing  that  the  nitro- 
gen, phosphoric  acid  and  potash  contained  iu  these 
materials  can  be  purchased  in  ton  lots  for  the 
prices  mentioned.  The  valuations  of  mixed  fertilizers, 
obtained  by  the  use  of  this  schediile,  are  entirely 
commercial;  they  are  not  intended  to  indicate  even  a 
possible  agricultural  value.  This  point  needs  to  be 
emphasized,  as  many  are  inclined  to  interpret  them 
as  not  only  guides  as  to  agricultural  value,  but  as 
positive  statements  of  such  value.  It  can  be  said, 
however,  that  those  who  do  so  do  not  familiarize 
themselves  with  the  discussions  that  usually  accom- 
pany reports  of  analyses.  The  different  trade  values 
given  for  the  nitrogen  and  phosphoric  acid  in  the 
two  grades  of  bone  represent  their  value  in  the  form 
of  ground  bone  and  of  bone  meal,  products  which 
are  distinctly  recognized  in  the  market,  and  which  are 
quoted  at  different  prices.  The  coarser  ground  bone 
is  lower  in  price  than  the  finer  bone  meal. 

The  accuracy  of ,  the  schedule  of  values  can  be 
shown  by  comparing  it  with  the  actual  prices  paid 
for  the  constituents  in  the  different  materials,  and 
such  comparisons  as  have  been  made  from  year  to 
year,  by  a  number  of  the  institutions  exercising  an 
analysis  control,  show  that  manufacturers  and  dealers 


OBJECTIONS   TO   COMMERCIAL   VALUES  159 

are  willing  to  sell  to  farmers  at  prices  corresponding 
very  closely  with  the  schedule.* 

A  value  is  placed  upon  the  insoluble  phosphoric 
acid  in  mixed  fertilizers,  not  because  all  insoluble  costs 
the  price  given,  but  because  in  mixtures  it  is  assumed 
that  the  phosphoric  acid  is  drawn  from  organic  sources, 
which  do  cost,  at  least,  the  price  given. 

There  are  arguments  both  in  favor  of  and  in  oppo- 
sition to  this  method  of  comparing  the  commercial 
values  of  mixed  fertilizers.  The  chief  arguments  in 
opposition  may  be  stated  as  follows: 

First,  that  the  prices  of  these  materials  vary,  and 
hence  in  order  to  represent  the  actual  commercial  value 
at  the  time  the  sales  are  made,  they  should  be  changed 
as  the  markets  change. 

Second,  the  valuations  are  misleading,  because  the 
farmer  does  not  clearly  understand  their  meaning,  and 
is  thus  guided  in  his  judgment  of  the  usefulness  or 
agricultural  value  of  a  fertilizer  by  the  stated  com- 
mercial value,  as  shown  by  this  method,  rather  than  by 
the  kind,  form  and  proportion  of  constituents  that 
may  be  contained  in  it,  and  upon  which  its  agricultural 
value  should  be  based. 

Third,  the  chemical  analysis  does  not  show  abso- 
lutely the  sources  of  the  materials,  and  thus  it  is 
difficult  to  place  a  true  commercial  value  upon  a  mix- 
ture. This  is  especially  true  of  organic  nitrogen, 
since  because  it  is  impossible  to  separate  the  amounts 
that  may  be  derived  from  different  materials,  a  uniform 

*See  Bulletins  Connecticut  and  New  Jersey  Experiment  Stations. 


160  FERTILIZERS 

value  is  placed  upon  the  total  nitrogen  found,  whether 
it  is  derived  from  the  best  forms,  as  dried  blood  and 
dried  meat,  or  whether  derived  from  horn  meal,  ground 
leather,  or  other  low-grade  forms  of  nitrogenous 
material.  This  encourages  the  use  of  low-grade 
products  by  unscrupulous  manufacturers,  to  the  real 
detriment  of  the  trade  as  a  whole. 

Fourth,  that  the  commercial  value  so  fixed  mili- 
tates against  the  use  of  certain  kinds  of  good  materials, 
and  in  favor  of  certain  kinds  of  poorer  materials. 
That  is,  a  valuation  of  2  cents  per  pound  for  insoluble 
phosphoric  acid  in  complete  fertilizers,  for  example,  is 
a  direct  encouragement  to  include  in  the  mixture  a 
considerable  proportion  of  the  insoluble  phosphoric 
acid  from  South  Carolina,  and  other  rock  phosphates, 
the  value  of  which  is  ignored  in  commercial  transac- 
tions ;  while  that  price  (2  cents)  does  not  give  a  fair 
value  to  the  phosphoric  acid  contained  in  bone,  tankage 
and  natural  guanos,  products  in  which  the  commercial 
value  of  the  insoluble  is  recognized, — that  is,  mixtures 
which  contain  bone  and  tankage,  and  which  furnish 
phosphoric  acid  largely  in  an  insoluble  form.  The 
valuation  fixed  for  this  form  is  too  low  to  fully 
represent  the  commercial  value  of  these  goods.  It  is 
also  said  that  the  trade  value  for  available  phos- 
phoric acid  in  the  mixtures  encourages  the  use  of 
superphosphates  from  the  rock  phosphates,  and  dis- 
courages the  use  of  superphosphates  from  bone-black, 
bone -ash  and  dissolved  bone,  because  the  trade  or 
commercial  values  represent  the  average  cost  of  availa- 
ble phosphoric  acid   in   the  superphosphates   from   all 


THU   ADVANTAGES    OF   VALUATIONS  161 

of  these,  while  the  latter  materials,  because  of  actual 
commercial  conditions,  cost  more  than  the  superphos- 
phates from  the  former. 

The  chief  arguments  in  favor  are: 

First,  that  it  is  not  asserted  that  the  system  shows 
absolutely  the  commercial  value  of  each  brand  at  the 
time  the  sales  are  made,  but  the  comparative  com- 
mercial value. 

Second.  They  are  not  misleading.  The  commercial 
valuations  are  not  intended  to  be  a  guide  as  to  the 
agricultural  value  of  a  fertilizer.  It  is  distinctly  stated 
in  the  reports  of  analyses  that  the  comparative  values 
are  purely  commercial. 

Third.  It  is  a  system  which  more  nearly  approaches 
perfection  than  any  other  that  has  been  devised,  is 
educative  in  its  tendency,  and  is  a  safe  guide,  in  the 
majority  of  instances,  as  to  the  charges  made  for 
mixing,  handling  and  selling  plant -food  contained  in 
the  different  brands.  If  the  analysis  is  properly  in- 
terpreted, as  already  indicated,  it  is  the  purchaser's 
fault  if  he  buys  poor  forms  of  plant -food  at  a  high 
price.  It  is  certainly  a  safer  guide  than  mere  name 
of  brand,  and  does  not  encourage  the  use  of  poor 
materials. 

Fourth.  Any  system  of  comparison  of  brands  must 
leave  a  great  deal  to  the  judgment  of  the  purchaser. 
He  must  interpret  for  himself  whether  he  would  rather 
that  his  phosphoric  acid  were  derived  from  one  source 
or  another,  whether  he  would  prefer  to  pay  a  higher 
price  for  insoluble  phosphoric  acid  in  acid  phosphate, 
and  have  the  remainder  soluble,  than  to  pay  the  same 


162  FEBTILIZEB8 

or  a  greater  price  for  the  insoluble  phosphoric  acid  in 
bone,  and  have  the  remainder  of  it  in  the  reverted 
form.  These  conditions  are  again  indicated  by  the 
analysis  which  accompanies  the  valuation ;  the  valua- 
tions are,  therefore,  not  to  be  used  in  total  disregard 
of  the  composition.  If  they  are  so  used,  it  is  not  the 
fault  of  the  sj'stem.  That  it  militates  against  the  use 
of  high-priced  superphosphates,  if  they  are  no  better 
than  the  lower- priced  ones,  is  no  argument  against 
the  system,  but  rather  for  it,  since  it  tends  toward  a 
readjustment  of  the  prices,  a  condition  that  must  be 
met  in  all  competitive  trades.  Furthermore,  the  valua- 
tion system  has  been  effective  in  driving  out  materials 
that  are  either  fraudulent  in  their  character  or  of  very 
low-grade.  It  is  impossible  to  obtain  a  high  valuation 
on  poor  materials,  and  in  the  majority  of  cases  de- 
pendence upon  valuations  alone  would  be  a  safe  guide 
as  to  the  comparative  agricultural  value  of  brands  of 
the  same  general  composition. 

CALCULATION   OF    COMMERCIAL  VALUES 

The  following  examples  illustrate  how  commercial 
values  of  complete  fertilizers  and  of  ground  bone  are 
calculated.  The  mixed,  or  complete  fertilizer,  contains 
the  three  forms  of  nitrogen,  three  of  phosphoric  acid, 
and  the  two  forms  of  potash.  In  the  bone,  it  is 
assumed  that  50  per  cent  of  the  meal  is  finer  than 
1-50  inch,  and  is,  therefore,  regarded  as  fine,  and  that 
50  per  cent  is  coarser  than  1-50  inch,  and  is,  therefore, 
regarded  as  coarse  ;    and  it  is  also  assumed  that   the 


CALCULATION   OF    COMMUBCIAL    VALUES        163 

proportions  of  the  nitrogen  and  phosphoric  acid  in 
the  fine  and  coarse  is  the  same ;  also,  that  the  analysis 
shows  the  bone  to  contain  4  per  cent  of  nitrogen  and 
20  per  cent  of  phosphoric  acid. 


A   Complete  Fertilizer 


i  or  lbs. 
per  100 


Lbs. 

per  ton 


Nitrogen,  as  nitrates  .    .    . 

"         "   ammonia  salts 

"         "   organic  matter 

Phosphoric  acid,  soluble  . 

"  "     reverted 

"  "     insoluble 

Potash,  as  muriate     .    .    . 

"        "   sulphate  .    .    . 


1 X  20  =  20 
1  X  20  =  20 
1  X  20  =  20 
8X20=160 
1  X  20  =  20 
1  X  20  ==  20 
5X20=100 
5X20=100 


3 

Value 

per  lb. 

cts. 

13.0 

14.0 

14.0 

4.5 

4.5 

2.0 

4.25 

5.0 


Estimated  value 

per  ton  of  each 

constituent.. 

=      $2  60 


Total  estimated  value  per  ton $25  95 

The  first  column  shows  the  per  cent  of  the  con- 
stituents contained,  which,  multiplied  by  20,  gives  the 
pounds  per  ton  in  the  second  column,  which,  multiplied 
by  the  schedule  prices  per  pound,  gives  the  valuation 
per  ton,  as  shown  in  the  fourth  column. 


Ground  Bone 


1  2 

i  or  lbs.  i  of 
per  fine- 
100       ness 

4  X  50  = 

4  X  50  = 

Phosphoric  (20  X  50  = 

acid    .   (20  X  50  = 


Nitrogen 


i  or  lbs. 
per  100 

■  2  in  fine, 

■  2  in  coarse.  X  20 
=  10  in  fine.      X  20 


Lbs. 
per  ion 

X20=   40    X 

40 

200 


:10  in  coarse.  X  20  =200 


X 
X 
X 


5 

Value 

per  lb. 

cts. 

13.5 

10.0 
4.0 
3.5 


Estimated 

vahie 

per  ton 

=  $5  40 

=  4  GO 

=  8  00 

=  7  00 


Total  estimated  value  per  ton $24  40 


164  FERTILIZERS 

The  first  column  of  figures  shows  the  per  cent, 
or  pounds  per  hundred,  of  the  constituents,  which  is 
multiplied  by  the  percentage  of  fineness,  which  gives 
the  percentage  or  pounds  per  hundred  of  fine  or 
coarse  in  the  third  column.  The  calculation  is  then 
finished  as  in  the  case  of  complete  fertilizers. 

THE    UNIFORMITY    OF    MANUFACTURED    BRANDS 

Another  point  which  consumers  of  fertilizers  are 
interested  in  is  the  reliability  of  the  various  brands. 
That  is,  they  desire  to  know  whether  a  brand  that 
shows  good  forms  of  nitrogen,  of  phosphoric  acid,  and 
of  potash  in  one  year  may  be  depended  upon  to  fur- 
nish approximately  the  same  the  following  year,  or 
whether  the  manufacturers  change  their  formulas  from 
year  to  year  to  conform  to  the  relative  cost  of  the 
different  materials :  that  is,  whether  when  nitrogen 
is  relatively  expensive  and  phosphoric  acid  is  rela- 
tively cheap,  they  introduce  a  larger  proportion  of 
phosphoric  acid  and  a  smaller  percentage  of  nitrogen; 
whether  when  organic  nitrogen  is  cheap  and  nitrate 
and  ammonia  nitrogen  are  dear,  they  change  the  pro- 
portions of  these  to  correspond  with  the  difference 
in  price,  in  order  to  retain  the  same  selling  price. 

This  is  an  important  point,  since  after  a  certain 
brand  has  been  shown  to  be  better  suited  than 
another  to  their  conditions  of  soil,  to  change  the 
formula,  both  in  reference  to  the  character  and  pro- 
portions, may  mean  to  the  purchaser  the  difference 
between  profit  and  loss. 


VNIFOBMITF   OF   MANUFACTURED    BRANDS    165 

Evidence  on  this  point  can  be  obtained  from  the 
reports  showing  the  results  of  the  analyses  of  the  dif- 
ferent brands  from  year  to  year,  and  a  careful 
study  of  these  shows  that  genuine  manufacturers  of 
fertilizers, — those  who  make  it  their  sole  business, 
rather  than  a  side  issue  or  an  adjunct  to  another  busi- 
ness,— can  be  fully  depended  upon  in  this  respect. 
They  know  that  the  farmer's  interest  is  their  interest, 
and  that  their  sales  will  depend,  other  things  being 
equal,  upon  the  increased  crop  results  that  the  farmer 
secures ;  that  the  permanency  and  success  of  their 
business  will  depend  upon  the  successful  and  profitable 
use  of  their  product ;  and  that  they  cannot  afford  to 
and  do  not  change  their  formulas  from  year  to  year, 
either  in  proportion  or  quality  of  constituents,  to  cor- 
respond with  the  changes  in  price  of  the  materials. 
Their  brands  can  be  depended  upon  to  furnish  prac- 
tically the  same  amount,  kind  and  proportion  of 
plant -food  from  year  to  year. 

The  value  of  a  fertilizer  depends  upon  the  kind, 
quality  and  form  of  plant -food,  as  shown  by  the 
analysis.  Value  does  not  depend  upon  who  the  manu- 
facturer is,  or  what  the  statements  may  be  concerning 
the  usefulness  of  special  manipulation,  nor  to  any 
great  extent  upon  special  formulas,  unless  the  farmer 
has  positive  knowledge  of  the  character  of  his  own 
conditions.  Formulas  derived  both  in  kind  and  pro- 
portion from  the  same  materials  will  do  equally  well 
under  the  same  conditions.  So  far  as  the  matter  has 
been  investigated,  there  is  no  specific  virtue  added  by 
what  is  claimed  to  be  the  "blending"  of  the  materials. 


166  FERTILIZERS 

In  the  whole  matter  of  the  purchase  of  fertilizers, 
no  guide,  however  good,  can  take  the  place  of  intel- 
ligence on  the  part  of  the  purchaser.  This  intelli- 
gence must  be  exercised  in  the  selection  of  forms  of 
plant -food,  in  the  preparation  of  formulas,  in  the 
interpretation  of  guarantees  and  of  commercial  values, 
and  in  the  method  of  using  the  fertilizer. 


CHAPTER  IX 

METHODS    OF    USE    OF  FEBTILIZEB8 

The  primary  object  in  the  use  of  a  commercial  fer- 
tilizer is  to  receive  a  profit  from  the  increase  in  the 
yield  of  crops  from  the  land  to  which  it  is  applied; 
and  this  may  be  derived  either  from  the  immediate 
crop,  or  from  the  larger  yield  of  a  number  of  crops. 
That  the  greatest  immediate  or  prospective  profit  may 
be  gained,  a  wide  knowledge  of  conditions  which  have 
either  a  direct  or  indirect  bearing  upon  the  result  is 
essential. 

CONDITIONS     WHICH     MODIFY     THE      USEFULNESS     OF 
FERTILIZERS 

In  fact,  the  controlling  conditions  surrounding  the 
matter  are  so  numerous  and  so  various  that  it  is  im- 
possible, with  our  present  knowledge,  to  lay  down 
positive  rules  for  our  guidance.  At  best,  only  sug- 
gestions can  be  offered. 

We  may  possess  a  full  knowledge  of  both  the  kind 
and  form  of  existing  fertilizer  supplies,  their  cost  and 
the  action  under  known  conditions  of  the  constituents 
contained  in  each,  as  well  as  their  maximum  capability 
for  increasing  the  crop,  but  together  with  this  knowl- 
edge, it   is  essential   that  we  should  know  how  these 

(167) 


168  FERTILIZERS 

facts  and  principles  must  be  applied  to  each  individual 
crop,  soil  and  condition,  and  yet  even  with  this,  abso- 
lute certainty  of  profit  is  not  guaranteed.  A  few  of 
the  more  important  conditions  which  control  the 
profitable  use  of  fertilizers  are,  therefore,  briefly  dis- 
cussed, in  order  to  arrive  at  a  better  understanding  of 
the  practical  suggestions  and  concrete  examples  given 
in  subsequent  chapters. 

Derivation    of   Soil    a    Chiide    as    to    its    Possible 
Deficiencies 

The  first  consideration  is  the  soil  itself,  and  its 
influence.  It  is  well  known  that  a  wide  difference 
exists  in  soils,  both  in  reference  to  their  chemical 
character  or  composition,  and  to  their  physical  proper- 
ties, each  having  a  direct  influence  in  determining  the 
effect  of  any  specific  application  of  fertilizers.  These 
differences  in  soils  are  due  to  changes  which  were 
wrought  in  the  surface  of  the  earth  during  its  forma- 
tion, and  which  are  continuing  in  a  small  way  at  the 
present  time.  It  is  believed  that  the  original  earth 
crust  contained  all  the  minerals  now  found  in  it,  but 
that  in  the  beginning  they  were  distributed  more  uni- 
fromly  throughout  its  mass,  and  that  the  soils  as  they 
exist  at  the  present  time,  and  as  a  result  of  the  direct 
disintegration  of  the  original  rock,  represent  a  very 
small  area  of  the  earth's  surface.  They  are  not  now 
constant,  but  variable  in  their  character.  The  various 
changes  that  have  taken  place  during  geologic  time 
have  resulted  in  the  breaking  up  of  the  original  rocks. 


bOILS   DIFFER  IN   CHEMICAL    COMPOSITION    169 

a  part  having  been  separated  meclianically  and  being 
represented  by  various  sizes  of  particles,  and  a  part 
rendered  soluble.  The  fragments  and  the  soluble  por- 
tions thus  separated  have  not  been  deposited  again  in 
the  same  proportions  as  they  existed  in  the  original 
rock,  which  has  caused  a  very  wide  variation  in  the 
chemical  composition  of  the  different  soil  deposits. 
The  process  and  its  results  may  be  shown  at  the  present 
time  in  the  wearing  away  of  rocks.  The  harder, 
sandy  particles  separate  mechanically,  and  because  of 
the  difference  in  the  size  of  the  particles,  the  coarser 
are  deposited  as  gravel  or  sand,  in  one  place,  and  the 
finer  particles  are  deposited  in  another,  making  the 
clay.  The  lime  enters  partly  into  solution  and  is  de- 
posited in  another  place,  and  so  on,  thus  giving  us 
sandy  soils,  clayey  soils  and  limy  soils,  all  differing 
from  each  other  in  their  amount  and  proportion  of  the 
essential  fertilizing  constituents,  as  well  as  in  their 
physical  qualities, — the  sandy  and  gravelly  making  the 
poorest  soils  because  the  particles  consist  very  largely 
of  quartz,  and  the  remainder  being  poor  in  phosphoric 
acid  or  potash.  The  clay  soils  are  frequently  rich  in 
minerals  containing  potash,  and  poor  in  those  con- 
taining lime  and  phosphoric  acid;  and  the  limestone 
soils  are  poor  in  potash  and  rich  in  lime,  and  fre- 
quently in  phosphates.  In  addition  to  these  soils, 
there  are  those  that  are  made  up  largely  of  vegetable 
matter,  due  to  the  accumulation  of  decaying  growths. 
These  are  frequently  rich  in  nitrogen  and  poor  in  all 
of  the  essential  mineral  constituents. 

Hence  it  is  that  in  the  use  of  a  commercial  fertilizer, 


170  FERTILIZERS 

at  least  for  certain  crops,  a  knowledge  of  ihe  nature 
of  soils  in  respect  to  the  possible  deflcieat  element  is 
important,  in  order  that  those  which  exist  in  abun- 
dance may  not  be  added  to,  but  that  they  may  be  sup- 
plemented by  such  an  abundance  of  the  deficient  ele- 
ments as  to  permit  the  acquirement  by  the  crops  of 
those  necessary  for  a  maximum  growth.  As  a  rule, 
potash  is  a  very  essential  constituent  of  manures  for 
sandy  soils,  not  only  because  all  crops  require  potash, 
but  because  they  require  it  in  relatively  large  amounts, 
and  because  in  sandy  soils  it  is  liable  to  exist  in 
minimum  amounts.  Potash  fertilization,  therefore,  is 
especially  useful  on  sandy  soils.  On  the  other  hand, 
in  clay  soils,  which,  as  a  rule,  contain  a  very  con- 
siderable proportion  of  potash  as  compared  with  sandy 
soils,  the  deficient  element  may  be  either  phosphoric 
acid  or  lime;  and  if  these  are  supplied  in  abundance, 
the  plant  will  be  able  to  secure  the  necessary  potash. 
In  a  limy  soil,  the  lime  and  phosphoric  acid,  and  per- 
haps the  potash,  may  be  in  sufficient  abundance  to 
cause  a  normal  growth  of  plant,  yet  the  nitrogen  may 
be  so  deficient  as  to  prevent  a  normal  growth. 

Physical  Imperfections  of  Sandy  Soils 

If  it  were  possible  to  distinctly  classify  soils  in 
respect  to  their  lack  of  one  or  more  of  the  essential 
constituents,  it  would  be  an  easy  matter  to  formulate 
rules  for  our  guidance  in  the  fertilization  of  these 
soils;  but  such  is  not  the  case.  Even  sandy  soils  vary 
widely   in   their   chemical   composition,    as   well   as   in 


SOILS   DIFFER    IN   PHYSICAL    CHARACTEB     171 

their  mechanical  or  physical  properties,  and  certain 
of  them  possess  such  a  physical  character  as  to  make 
it  impossible  to  grow  maximum  crops  even  though 
the  essential  elements  are  all  supplied  in  sufficient 
abundance.  The  constituent  particles  are  too  coarse, 
and  thus  make  the  soils  so  open  and  porous  that 
they  too  freely  admit  the  air,  water  and  warmth,  and 
thus  results  a  very  rapid,  drying  and  heating  of  the 
soil,  with  a  premature  ripening  and  burning  of  the 
crops.  The  phosphates  or  the  potash  compounds  ap- 
plied are  not  readily  fixed,  and  suffer  an  immediate 
loss  as  soon  as  rain  falls  in  such  amounts  as  to 
cause  a  leaching  from  them. 

Physical  Imperfections  of  Clay  Soils 

In  clay  soils,  the  physical  conditions  are  quite  the 
reverse.  All  clay  soils  do  not  have  the  same  general 
composition,  and  they  differ  widely  in  their  physical 
qualities.  Certain  of  them  possess  a  reasonably  good 
texture,  and  permit  the  absorption  of  the  food  applied, 
as  well  as  its  gradual  distribution  throughout  the 
mass  by  the  percolation  of  the  water  through  them; 
while  certain  others  are  so  compact,  owing  to  the 
finely  divided  particles,  that  even  though  they  were 
abundantly  supplied  with  all  or  the  necessary  mineral 
constituents,  profitable  crops  could  not  be  grown 
because  the  roots  could  not  readily  penetrate,  and 
because  the  water  falling  upon  the  land  would  not 
readily  pass  through,  but  remain  upon  the  surface. 

In   the   case   of   soils  with   an   abundance  of   lime. 


172  FERTILIZERS 

physical  qualities  also  exercise  a  very  considerable 
influence,  even  though  there  is  a  sufficient  supply  of  all 
of  the  fertility  elements.  Certain  of  them  are  too  cold, 
others  are  too  dry,  and  the  mechanical  condition  is 
such  as  to  prevent  the  proper  and  uniform  growth  of 
plants.  It  must  be  remembered,  then,  that  only  gen- 
eral rules  apply  in  the  use  of  fertilizers  upon  soils  of 
the  different  classes,  and  that  they  are  modified  by 
both  the  chemical  composition  and  the  mechanical  con- 
dition of  the  soils.  The  best  use  of  a  fertilizer, — that 
is,  the  greatest  proportionate  return  of  plant -food  in  the 
crop,  all  things  considered, — is  obtained  from  its  ap- 
plication upon  soils  that  possess  "condition,"  or  that 
are  well  cultivated  or  managed.  Full  returns  cannot 
be  expected  when  they  are  applied  upon  soils  that  are 
too  wet  or  too  dry,  too  porous  or  too  compact,  or  too 
coarse  or  too  fine.  It  is  important  that  even  the  best 
soils  should  be  properly  prepared,  and  it  is  infinitely 
more  important  that  those  which  possess  poor  mechan- 
ical condition  should  be  improved  in  this  respect, 
before  large  expenditures  are  made  for  fertilizers. 

The  Influence  of  Previous  Treatment  and  Cropping 

In  the  next  place,  the  previous  treatment  and 
cropping  of  soils  should  guide  in  the  use  of  fer- 
tilizers, since  soils  of  the  same  natural  character, 
located  equally  well,  will  not  always  show  the  same 
results  from  the  application  of  fertilizers,  because  in 
the  one  case  the  cropping  has  been  such  as  to  result 
in  the  rapid  exhaustion  of  one,  rather  than  the  three 


INFLUENCE    OF    PREVIOUS    C BOPPING  173 

specific  fertilizer  elements ;  while  in  the  other,  the 
cropping  may  have  been  quite  as  severe,  but  has  been 
helpful  because  judicious  rotations  have  been  used  and 
improved  methods  practiced.  It  may  be  that  in  the 
one  case,  there  may  have  been  a  continuous  cropping 
of  wheat,  for  example,  and  only  the  grain  sold  from 
the  farm,  in  which  case  there  would  be  a  much  more 
rapid  exhaustion  of  the  nitrogen  and  phosphoric 
acid  than  of  the  potash  ;  and  if  this  continuous 
wheat -cropping  has  been  continued  for  a  long  time, 
an  application  of  the  phosphates  only  may  result  in 
quite  as  large  an  increase  in  crop  as  if  both  phos- 
phates and  potash  salts  were  applied,  because  the 
potash  exhaustion  has  been  less  i^pid  than  that 
of  the  phosphoric  acid,  and  the  addition  of  potash 
would  simplj'  add  to  the  probably  abundant  quantities 
already  there.  On  the  other  hand,  if  the  cropping 
has  been  timothy  hay,  the  removal  of  the  potash 
would  have  been  greatly  in  excess  of  the  phosphoric 
acid,  and  consequently  a  fertilization  with  a  greater 
proportion  of  potash,  or  even  this  element  alone,  of 
the  minerals,  may  result  in  quite  as  large  returns 
as  if  the  fertilization  had  consisted  of  both  phosphoric 
acid  and  potash.  In  fact,  if  the  land  had  been 
cropped  continuously  with  tobacco,  cotton,  potatoes, 
or  other  crop,  there  is  likely  to  be  a  much  larger 
removal  proportionately  of  some  one  element,  rather 
than  proportionate  amounts  of  all.  This  practice 
results  in  a  disproportionate  removal  of  the  constitu- 
ents, and  in  order  to  bring  the  land  back  to  its 
capacity    for    maximum     production,    or    to    equalize 


174  FERTILIZERS 

matters  in  this  respect,  it  is  necessary  to  add  to  the 
soil  the  constituents  removed  in  amounts  in  excess 
of  the  others.  On  the  other  hand,  the  cropping  may 
have  been  such  as  to  be  fully  as  exhaustive  in  the 
sense  that  the  total  quantity  of  constituents  removed 
is  quite  as  great,  though  since  they  are  removed  in 
more  uniform  proportions,  the  period  of  profitable 
cropping  is  extended,  and  the  fertility  needed  includes 
all  the  essential  elements,  rather  than  one  or  two. 
That  is,  the  grain,  hay  and  potatoes  may  have  been 
grown  in  rotation,  each  removing  one  or  the  other  in 
greater  proportion,  but  because  they  differ  with  each 
crop,  no  one  is  exhausted  before  the  other;  and  thus 
when  the  land  -reaches  the  time  when  it  would  no 
longer  profitably  grow  those  crops,  an  application 
then  of  all  of  the  constituent  elements  would  result  in 
a  greater  and  more  profitable  increase  in  crop  than 
if  the  fertilizer  contained  one  constituent  only.  The 
previous  treatment  and  cropping  of  soils,  therefore, 
is  an  important  guide  in  determining  the  most 
economical  method  of  fertilization. 

Furthermore,  in  this  matter  of  cropping  as  a  guide 
to  possible  need  of  fertilization,  it  must  be  remem- 
bered that  a  continuous  one -crop  practice  is  more 
productive  of  total  loss  of  constituents  than  a  prac- 
tice which  includes  such  renovating  crops  as  clover, 
or  one  which  permits  of  a  more  constant  occupation 
of  the  land,  since  in  the  former,  the  introduction  of 
clover  reduces  the  need  for  nitrogen  fertilization,  and 
in  the  latter,  the  vegetable  matter  is  not  so  rapidly 
used    up,    and    the    loss   of    mineral    constituents    by 


INFLUENCE    OF    CEABACTER    OF    CROP  175 

mechanical   and  other  means   is   very   much   reduced, 
because  of  the  constant  occupation  of  the  land. 

The  Influence  of  Character  of  Crop 

The  financial  result  from  the  application  of  fer- 
tilizers is  also  influenced  in  a  very  large  degree  by 
the  character  of  the  crop  itself,  whether  the  value 
of  an  increase  in  crop  as  great  as  can  be  expected 
from  a  definite  application  is  high  or  low ;  and  on 
this  basis,  crops  may  be  classified  into  two  general 
groups  ;  first,  those  which  possess  a  high  fertility,  and 
which,  as  a  rule,  possess  a  relatively  low  commercial 
value;  and  second,  those  which  possess  a  low  fertility 
value  and  a  relatively  high  commercial  value.  In  the 
first  class  are  included  the  cereal  and  forage  crops, 
as  corn,  oats,  wheat,  hay,  buckwheat,  cotton  and 
tobacco,  and  in  the  second  are  included  the  various 
vegetable  and  fruit  crops.  This  classification,  and 
its  importance,  may  be  illustrated  by  the  following 
examples  : 

A  ton  of  wheat,  at  $1  per  bushel,  will  bring 
$33,33.  Its  sale  removes  from  the  farm  38  pounds 
of  nitrogen,  19  of  phosphoric  acid,  and  13  of  potash. 
At  prevailing  prices  for  these  constituents,  it  would 
cost  $6.50  to  return  them  to  the  farm. 

A  ton  of  asparagus  shoots,  at  10  cents  per  pound 
bunch,  will  bring  $200.  Its  sale  removes  from  the 
farm  6  pounds  of  nitrogen,  2  of  phosphoric  acid  and 
6  of  potash,  which  could  be  returned  for  but  little 
more   than   $1. 


176  FERTILIZERS 

A  ton  of  timothy  hay  will  bring  $10.  Its  sale 
removes  from  the  farm  18  pounds  of  nitrogen,  7  of 
phosphoric  acid  and  28  of  potash,  amounts  that 
would    cost   $4. 

A  ton  of  apples  will  bring  in  an  ordinary  season 
$20.  It  removes  less  than  3  pounds  of  niti'ogeu,  1  of 
phosphoric  acid  and  4  of  potash,  which  would  cost 
less  than  60  cents  to  return  to  the  land. 

It  is  thus  shown  that  crops  like  wheat  and  hay 
possess  a  relatively  low  commercial  value,  and  yet 
carry  away,  when  sold,  a  very  considerable  amount 
of  the  fertilizing  constituents,  while  vegetables  and 
fruits,  as  illustrated  by  the  asparagus  and  the  apples, 
have  a  high  commercial  or  market  value,  and  carry 
away  but  minimum  amounts  of  the  fertilizing  con- 
stituents. This  distinctive  character  of  crops,  while 
not  an  absolute  guide  as  to  the  profits  that  may  be 
obtained  from  the  use  of  fertilizers, — since  the  cost  of 
production  varies  widely  for  each  class, — is  instruc- 
tive in  showing  that  those  of  a  low  commercial  value 
are  more  exhaustive  than  the  other  class,  or  those  of 
a  high  market  value,  and  is  certainly  suggestive, 
pointing  out  the  necessity  for  judgment  in  the  ap- 
plication of  fertilizers  that  shall  be  made  in  the 
case   of    crops   of    the   different   groups. 

The  Kind  of  Farming,  Whether  ^^ Extensive  or  Intensive" 

Another  very  important  consideration,  and  one  which 
exercises  an  influence,  is  whether  the  farming  engaged 
in    is    "extensive"    in    its    character,    or   "intensive;" 


1 


CHARACTERISTICS   OF   GROWTH  Vll 

whether  the  purpose  or  idea  is  to  simply  supplement  the 
stores  of  plant -food  in  the  soil,  or  whether  the  object 
is  to  ensure  an  abundance  of  all  forms  of  constituents 
under  all  reasonable  conditions,  in  order  that  a 
maximum  production  may  be  secured. 

PLANTS    VARY    IN    THEIR    POWER   OF    ACQUIRING  FOOD 

In  the  next  place,  the  character  or  feeding  capacity 
of  the  plant  and  its  season  of  growth  should  be  con- 
sidered, that  systematic  methods  may  be  adopted,  and 
thus  not  only  that  waste  of  fertilizing  materials  may 
be  avoided,  but  that  the  applications  may  be  made  at 
such  times  and  in  such  amounts  as  will,  other  things 
being  equal,  promote  the  greatest  increase  per  unit 
of    applied  food. 

While  each  plant  possesses  individual  characteristics 
which  distinguish  it  from  all  others,  for  our  purpose 
they  may  again  be  classified  into  general  groups  which 
possess  somewhat  similar  characteristics,  particularly  as 
to  their  method  and  time  of  growth  and  their  capacity 
for  acquiring  food  from  soil  sources. 

Characteristics  of  the  Cereal  Group 

The  cereals  possess  distinct  characteristics  of 
growth.  The  roots  branch  just  below  the  surface,  and 
each  shoot  produces  feeding  roots,  which  distribute 
themselves  in  every  direction,  and  thus  absorb  food 
from  the  lower  layers  of  the  soil  as  the  plant  grows 
older.    Because  of  their  wide  root  system,  and  because 


178  FERTILIZERS 

of  the  character  of  their  feeding  rootlets,  they  are 
able  readily  to  acquire  food  from  the  insoluble  phos- 
phates and  potash  compounds  of  the  soU,  though  they 
are  unable  to  feed  to  any  extent  upon  the  insoluble 
nitrogen.  Furthermore,  inasmuch  as  the  most  rapid 
development  of  many  of  these  crops  takes  place  early 
in  the  summer,  before  the  conditions  are  favorable  for 
the  rapid  changing  of  organic  nitrogen  into  nitrates, 
they  are,  with  the  exception  of  Indian  corn  (maize), 
specifically  benefited  by  early  applications  of  nitrogen 
in  the  form  of  nitrate.  The  corn,  on  the  other  hand, 
which  makes  its  most  rapid  growth  after  the  other 
cereals  are  harvested, —  in  July  or  August, — when 
the  conditions  are  particularly  favorable  for  the  de- 
velopment of  nitrates,  do  not  usually  require  as  large 
proportions  of  nitrogen  as  of  the  mineral  constituents, 
particularly  the  phosphates.  That  is,  wheat,  rye,  oats 
and  barley  are  specifically  benefited  by  the  early  appli- 
cation of  quickly  available  nitrogen. 

Characteristics  of  Grasses  and  Clovers 

Forage  crops,  including  both  the  grasses  and  clovei-s, 
constitute  another  group,  in  so  far  as  their  use  is  con- 
cerned, though  possessing  marked  distinguishing  char- 
acteristics. Of  the  grasses,  nearly  all  species  are 
perennial,  though  their  length  of  life  depends  upon 
the  method  of  cropping  and  upon  the  character  of 
the  soil.  They  send  their  fibrous  roots  into  the  sur- 
face soil  in  the  same  manner  as  the  cereals,  though 
they  differ  from  them  in  forming  a  set  of  buds^  which 


CHABACTEBISTICS    OF    OBOWTE  179 

become  active  in  the  late  summer  and  develop  new 
roots  and  shoots.  They  resemble  the  cereals  in  their 
power  of  acquiring  mineral  food,  and  are  even  more 
benefited  by  the  application  of  nitrogen,  since  the 
chief  object  in  their  use  is  to  obtain  the  nitrogenous 
substances  contained  in  leaf  and  stem  in  the  form  of 
pasture,  forage  or  hay,  rather  than  the  matured  grain. 
Hence,  nitrogen,  which  promotes  this  form  of  growth, 
is  an  important  constituent,  and  under  any  conditions 
there  should  be  a  liberal  supply  provided. 

The  clovers,  on  the  other  hand,  are  not  perennial, 
with  the  partial  exception  of  "white"  or  "Dutch" 
clover,  and  with  this  exception  they  all  possess  a  tap- 
root, which  penetrates  downward,  and  as  it  descends, 
throws  out  fibrous  roots  into  the  various  layers  of 
soU.  They  are  capable  of  readily  acquiring  their 
mineral  food,  both  because  of  their  large  root  systems 
and  because  of  the  character  of  the  roots.  They,  how- 
ever, differ  in  one  very  important  particular  from  the 
cereals  and  grasses,  in  that  under  proper  conditions, 
as  already  pointed  out  (p.  118),  they  are  capable  of 
acquiring  their  nitrogen  from  the  air.  Thus  with 
liberal  dressing  of  only  phosphoric  acid  and  potash, 
maximum  crops  may  be  secured.  They  are  "nitrogen 
gatherers,"  and  the  tendency  of  their  growth  is  to  im- 
prove the  soil  for  the  nitrogen  consumers,  or  for  those 
that  obtain  their  nitrogen  only  from  soil  sources. 

Boot  Crops 

Another  class  of  plants,  differing  from  those  already 
described,   includes  the  root   crops,  as  beets,  mangels, 


180  FERTILIZERS 

turnips  and  carrots.  These  plants  cannot  make  ready 
use  of  the  insoluble  mineral  constituents  of  the  soil. 
Hence,  in  order  to  insure  full  crops,  they  must  be 
liberally  supplied  with  available  food.  Of  the  three 
classes  of  fertilizing  constituents,  the  phosphates  are 
especially  useful  for  turnips,  while  the  slower -growing 
beets  and  carrots  require  that  the  nitrogen  shall  be  in 
quickly  available  forms.  The  proper  fertilization  of 
sugar  beets,  for  example,  is  of  gi*eat  importance,  since 
not  only  is  the  yield  affected  by  fertilization,  but  the 
quality  of  the  beet  for  the  production  of  sugar. 

White  potatoes  and  sweet  potatoes,  the  one  a 
tuber,  the  other  an  enlarged  root,  constitute  another 
class  which  does  not  possess  strong  foraging  powers. 
They  require  their  food  in  soluble  and  available  forms, 
and  with  suitable  soils  potash  is  the  ingredient  that 
is  especially  useful  in  the  manures  applied. 

Marliet- garden  Crops 

Another  group  of  crops  is  distinguished  as  a  class, 
not  so  much  because  of  their  peculiar  habits  of  growth 
as  because  of  the  objects  of  their  growth,  though 
this  latter  fact  has  a  very  important  bearing  upon 
economical  methods  of  fertilization.  This  class  in- 
cludes what  are  called  "market -garden  crops,"  as 
lettuce,  beets,  asparagus,  celery,  turnips,  cucumbers, 
melons,  sweet  com,  beans,  peas,  radishes,  and  various 
others.  The  particular  object  in  raising  these  is  to 
secure  rapidity  in  growth,  and  thus  to  insure  high 
quality,  which   is  measured   by  the  element  of    succu- 


FBUIT   CB0P8   A    DISTINCT    CLASS  181 

lence.  In  order  that  this  may  be  accomplished,  they 
must  be  supplied  with  an  abundance  of  available 
plant -food,  and  since  nitrogen  is  the  one  element 
which  more  than  any  other  encourages  and  stimulates 
leaf  and  stem  growth,  its  use  is  especially  beneficial 
to  all  of  these  crops.  They  must  not  lack  for  this 
element  in  any  period  of  their  growth,  though,  of 
course,  a  sufficiency  of  minerals  must  be  supplied  in 
order  that  the  nitrogen  may  be  properly  utilized. 
Because  of  their  high  commercial  value,  the  quantity 
of  plant -food  applied  may  be  greatly  in  excess  of  that 
for  any  other  of  the  groups,  and  profits,  as  a  rule,  are 
measured  by  this  excess  rather  than  by  the  proportion 
of  the  elements. 

Fruit    Crops 

Another  distinct  class  of  crops,  though  differing 
materially  in  their  individual  characteristics,  as  well  as 
in  their  time  and  period  of  growth,  are  the  fruits. 
These  differ  from  most  other  crops,  in  that  a  longer 
season  of  preparation  is  required,  in  which  the  growth 
may  be  so  directed  as  to  prepare  the  plant  or  tree  for 
the  proper  development  of  a  different  kind  of  product, 
namely,  fruit,  as  distinct  from  grain  or  seed  in  the 
cereals,  or  succulence  in  the  vegetable  crops.  The 
fruit  differs  in  its  characteristics  from  the  ordinary 
farm  crops,  in  that  its  growth  and  development  require 
a  little  different  treatment,  since  it  is  necessary  that 
there  shall  be  a  constant  transfer  of  food  from  the 
tree  to  the  fruit  throughout  the  entire  growing  season. 
The  growth  of  each  succeeding  year  of   tree  and  fruit 


182  FERTILIZERS 

is  dependent,  not  altogether  upon  the  food  acquired 
during  the  year,  but  as  well  upon  that  acquired  in  the 
previous  year,  and  which  has  been  stored  up  in  bud 
and  branches.  A  knowledge  of  the  habits  of  growth, 
the  period  of  growth  and  the  object  of  the  growth  of 
this  class  is,  therefore,  useful  as  a  guide  to  the  eco- 
nomical supply  of  the  essential  elements  of  growth. 
These  crops  must  be  provided  with  food  that  will  en- 
courage a  slow  and  continuous  rather  than  a  quick 
growth  and  development. 

SYSTEMS    OF    FERTILIZING}    SUGGESTED 

A  careful  review  of  the  foregoing  facts  furnishes 
abundant  evidence  of  the  impracticability  of  attempts 
to  give  information  concerning  the  use  of  fertilizers 
that  will  apply  equally  well  under  all  of  the  conditions 
of  farming  that  may  occur.  Nevertheless,  there  have 
been  a  number  of  methods  or  sj'stems  of  fertilization 
suggested,  each  of  which  possesses  one  or  more  points 
of  advantage. 

A  System  Based  Upon  the  Specific  Influence  of  a 
Single  Element 

The  one  which  has  perhaps  received  the  most  atten- 
tion, doubtless  largely  because  one  of  the  first  pre- 
sented, and  in  a  very  attractive  manner,  is  the  system 
advocated  by  the  celebrated  French  scientist,  George 
Ville.  This  system,  while  not  to  be  depended  upon 
absolutely,    suggests    lines    of    practice   which,    under 


SYSTEMS    OF    FERTILIZING  183 

proper  restrictions,  may  be  of  very  great  service.  In 
brief,  this  method  assumes  that  plants  may  be,  so  far 
as  their  fertilization  is  concerned,  divided  into  three 
distinct  groups.  One  group  is  specifically  benefited  by 
nitrogenous  fertilization,  the  second  by  phosphatic, 
and  the  third  by  potassic.  That  is,  in  each  class  or 
group,  one  element  more  than  any  other  rules  or 
dominates  the  growth  of  that  group,  and  hence  each 
particular  element  should  be  applied  in  excess  to  the 
class  of  plants  for  which  it  is  a  dominant.  In  this 
system  it  is  asserted  that  nitrogen  is  the  dominant 
ingredient  for  wheat,  rye,  oats,  barley,  meadow  grass, 
and  beet  crops.  Phosphoric  acid  is  the  dominant  fer- 
tilizer ingredient  for  turnips,  Swedes,  Indian  corn 
(maize),  sorghum  and  sugar  cane;  and  potash  is  the 
dominant  or  ruling  element  for  peas,  beans,  clover, 
vetches,  flax  and  potatoes.  It  must  not  be  understood 
that  this  system  advocates  only  single  elements,  for  the 
others  are  quite  as  important  up  to  a  certain  point, 
beyond  which  they  do  not  exercise  a  controlling 
mfluence  in  the  manures  for  the  crops  of  the  three 
classes.  This  special  or  dominating  element  is  used  in 
greater  proportion  than  the  others,  and  if  soils  are  in 
a  high  state  of  cultivation,  or  have  been  manured  with 
natural  products,  as  stable  manure,  they  may  be  used 
singly  to  force  a  maximum  growth  of  the  crop.  Thus, 
a  specific  fertilization  is  arranged  for  the  various 
rotations,  the  crop  receiving  that  which  is  the  most 
useful.  There  is  no  doubt  that  there  is  a  good  scien- 
tific basis  for  this  system,  and  that  it  will  work  well, 
particularly    where    there    is   a   reasonable    abundance 


184  FERTILIZERS 

of  all  of  the  plant-food  constituents,  and  where  the 
mechanical  and  physical  qualities  of  soil  are  good, 
though  its  best  use  is  in  "intensive"  systems  of  prac- 
tice. It  cannot  be  depended  upon  to  give  good  results 
where  the  land  is  naturally  poor,  or  run  down,  and 
where  the  physical  character   also  needs  improvement, 

A  System   Based    Upon   the  Necessity  of  an  Abundant 
Supply  of  the  Minerals 

Another  system  which  has  been  urged,  notably  by 
German  scientists,  is  based  upon  the  fact  that  the 
mineral  constituents,  phosphoric  acid  and  potash, 
form  fixed  compounds  in  the  soil,  and  are,  therefore, 
not  likely  to  be  leached  out,  provided  the  land  is  con- 
tinuously cropped.  They  remain  in  the  soil  until  used 
by  growing  plants,  while  the  nitrogen,  on  the  other 
hand,  since  it  forms  no  fixed  compounds  and  is 
perfectly  soluble  when  in  a  form  useful  to  plants, 
is  liable  to  loss  from  leaching.  Furthermore,  the 
mineral  elements  are  relatively  cheap,  while  the  nitro- 
gen is  relatively  expensive,  and  thus  that  the  eco- 
nomical use  of  this  expensive  element,  nitrogen,  is 
dependent  to  a  large  degree  upon  the  abundance  of 
the  mineral  elements  in  the  soil.  It  is,  therefore, 
advocated  that  for  all  crops  and  for  all  soils  that  are 
in  a  good  state  of  cultivation,  a  reasonable  excess  of 
phosphoric  acid  and  potash  shall  be  applied,  sufficient 
to  more  than  satisfy  the  maximum  needs  of  any  crop, 
and  that  the  nitrogen  be  applied  in  active  forms,  as 
nitrate   or   ammonia,    and    in   such   quantities   and   at 


MINERAL    SUPPLIES    ADVANTAGEOUS  185 

such  times  as  will  insure  the  minimum  loss  of  the 
element  and  the  maximum  development  of  the  plant. 
The  supply  of  the  mineral  elements  may  be  drawn 
from  the  cheaper  materials,  as  ground  bone,  tankage, 
ground  phosphates  and  iron  phosphates,  as  their 
tendency  is  to  improve  in  character;  potash  may  come 
from  the  crude  salts.  Nitrogen  should  be  applied 
chiefly  as  nitrate  of  soda,  because  in  this  form  it  is 
immediatel}'  useful,  and  thus  may  be  applied  in  frac- 
tional amounts,  and  at  such  times  as  to  best  meet 
the  needs  of  the  plant  at  its  different  stages  of 
growth,  with  a  reasonable  certainty  of  a  maximum 
use  by  the  plants.  Thus  no  unknown  conditions  of 
availability  are  involved,  and  when  the  nitrogen  is  so 
applied,  the  danger  of  loss  by  leaching,  which  would 
exist  if  it  were  all  applied  at  one  time,  is  obviated. 

This  method  also  possesses  many  advantages,  par- 
ticularly where  the  "intensive"  system  is  practiced, 
though  it  is  also  useful  in  quickly  building  up  worn- 
out  soils,  or  those  naturally  poor,  because  in  any  case 
these  must  be  provided  with  liberal  supplies  of  the 
minerals,  and  when  these  ojily  are  applied,  the  im- 
mediate outlay  is  far  less  than  if  the  expensive  ele- 
ment, nitrogen,  were  included;  and  a  greater  economy 
in  the  use  of  nitrogen  is  accomplished  if  it  is  added 
in  small  amounts  when  required.  Besides,  in  the  im- 
provement of  soils,  the  liberal  application  of  the 
minerals  is  conducive  to  an  abundant  growth  of  the 
legumes,  which  are  able  to  acquire  their  nitrogen 
from  the  air,  thus  reducing  to  some  extent  the  outlay 
for   this  expensive  element.     This   system   is  strongly 


186  FERTILIZERS 

recommended  where  cheap  phosphatic  and  potassic 
materials  are  readily  accessible,  as  is  the  case  in  those 
countries  where  it  is  successfully  used. 

A   System   Based   on   the   Needs   of  the   Plants  for 

the  Different   Elements  as   Shown   by 

Chemical   Analysis 

Another  system  of  fertilization  is  based  upon  the 
theory  that  the  different  plants  should  be  provided 
with  the  essential  elements  in  the  proportions  in 
which  they  exist  in  the  plants,  as  shown  by  chemical 
analysis.  Different  formulas  are,  therefore,  recom- 
mended for  each  crop,  the  constituents  of  which  are 
so  proportioned  as  to  meet  its  full  needs.  This 
method,  if  care  is  taken  to  supply  an  abundance  of 
all  the  necessary  constituents,  may  result  in  a  com- 
plete though  perhaps  not  an  economical  feeding  of 
the  plant,  since  it  assumes  that  a  plant  which  con- 
tains a  larger  amount  of  one  constituent  than  of 
another  requires  more  of  that  constituent  in  the  fer- 
tilizer than  of  the  others..  It  does  not  take  into  con- 
sideration the  fact  that  the  plant  which  contains  a 
larger  amount  of  one  element  than  another  may  pos- 
sess a  greater  power  of  acquiring  it  than  one  which 
contains  a  smaller  amount. 

Neither  does  this  system  take  into  consideration, 
as  already  pointed  out  ( p.  178 ) ,  that  the  period  or 
time  of  growth  of  the  plant  also  exercises  a  consider- 
able influence  in  indicating  the  capability  of  the  plant 
to  acquire  its  necessary   food  from   the   stores   of  the 


FEBTILIZING  POT-PLANTS  187 

soil,  as  may  be  illustrated  by  wheat  and  Indian  corn, 
which  both  contain  a  relatively  high  content  of 
nitrogen.  Under  good  conditions  of  soil,  wheat  is 
specifically  benefited  by  heavy  dressings  of  quickly 
available  nitrogen.  Corn  is  not,  and  one  reason  is, 
that  they  possess  different  powers  of  acquiring  food, 
due,  to  a  considerable  extent,  to  the  difference  in 
their  time  of  growth,  as  well  as  to  the  period  or  time 
of  their  most  rapid  growth. 

This  method  may,  however,  be  applied  with  very 
great  advantage  in  greenhouse  work,  or  in  growing 
market -garden  crops,  where  the  amounts  in  the  soil 
are  not  regarded  as  of  importance,  and  excessive 
amounts  of  all  are  added.  The  system  has  been 
elaborated  to  a  great  degree  of  nicety  for  the  grow- 
ing of  greenhouse  crops,  flowers,  and  foliage  plants, 
so  much  so  that  now  artificial  manure  cartridges  are 
prepared,  which  contain  the  amounts  and  kinds  of 
food  shown  by  the  analysis  of  the  different  plants 
to  be  needed  for  their  growth  and  full  development. 
"The  manure  has  the  form  of  a  fine  powder,  enclosed 
within  a  metallic  wrapper,  and  firmly  compressed  into 
the  shape  of  a  cartouche  or  capsule,  cylindrical  in 
form,  about  three -fourths  inch  across  and  one -half 
inch  in  depth.  It  is  simply  thrust  into  the  soil  of 
the  pot  to  a  depth  of  one -half  or  one  inch,  and 
allowed  to  remain.  After  a  time  it  is  found  that  the 
fertilizer  gradually  disappears,  and  at  length  nothing 
is  left  but  the  little  pill-box-like  wrapper,  which 
originally  contained  the  mixed  fertilizing  powder,"* 


•"The  Gardener's  Chronicle,"  London,  England. 


188  FERTILIZERS 

A   System   in    Which   the   Fertilizer  is  Applied   to   the 
^^ Money   Crop^^  in   the   Rotation 

Another  system  is  also  recommended,  which  is 
well  adapted  for  "extensive"  farming,  where  the  ma- 
jority of  crops  which  are  grown  in  rotation  possess 
a  high  fertility  value  and  a  low  commercial  value, 
and  where  one  crop  is  regarded  as  the  chief  "money- 
maker." The  system  demands  that  to  this  crop  shall 
be  applied  such  an  abundance  of  plant -food  as  to 
insure  a  continuous  feeding,  and  a  consequent  max- 
imum production,  even  though  adverse  conditions 
intervene.  Thus  by  a  liberal  supply  of  food,  a  money 
crop  is  secured  which  is  as  large  as  climate  and  sea- 
sonal conditions  will  permit,  though  which  does  not 
require  all  of  the  food  applied.  Hence  the  residue 
may  be  depended  upon  to  fully  nourish  the  remaining 
crops  in  the  rotation,  or  at  least  the  immediately  suc- 
ceeeding  ones,  thus  saving  direct  outlay  for  them. 
This  system  may  be  illustrated  as  follows  : 

On  soils  in  good  physical  condition,  and  naturally 
well  adapted  for  growing  potatoes,  this  crop  is  se- 
lected as  the  "money-maker"  in  the  rotation,  which 
consists  of  com,  potatoes,  wheat,  clover  and  hay. 
The  potato  crop  is  fertilized  so  liberally,  say  with 
1,500  pounds  per  acre  of  a  fertilizer  containing  — 

Nitrogen 4% 

Phosphoric  acid 6% 

Potash 10% 

as  to  insure  its  maximum  growth  under  average  con- 
ditions.     The   removal    of    a    large    crop   would    still 


IBRATIONAL    SYSTEM    OF   FERTILIZING         J 89 

leave  a  large  residue  of  plant -food,  which  would  pro- 
vide the  following  wheat  crop  with  at  least  all  of  the 
mineral  elements  necessary  to  produce  a  maximum 
crop.  If  the  wheat  does  not  show  vigorous  growth  in 
the  spring,  it  is  lightly  top-dressed  with  nitrate  of 
soda,  which  not  only  feeds  it  directly  with  nitrogen, 
but  strengthens  and  invigorates  the  plant,  enabling 
it  to  secure  the  minerals  needed.  The  removal  of  a 
large  crop  still  leaves  an  unused  residue,  upon  which 
the  clover  crop  following  is  also  able  to  make  a  maxi- 
mum growth,  and  thus  three  crops  are  fertilized  with 
the  one  application.  The  hay  is  either  fertilized  with 
both  the  minerals  and  nitrogen,  or  lightly  top-dressed 
with  nitrogen  early  in  the  spring.  The  yard  manure, 
accumulated  from  the  residue  of  straw,  hay  and  corn, 
is  applied  to  the  corn,  which,  being  a  gross  feeder, 
is  able  to  obtain  from  this  an  abundance.  Thus,  by 
the  heavy  application  of  fertilizer  upon  the  "money 
crop,"  all  the  crops  in  the  rotation  are  benefited. 

This  method  possesses  many  valuable  features,  and 
is,  perhaps,  quite  as  well  adapted  as  any  other  for  this 
system  of  farm  practice. 

An  Irrational  System 

The  most  expensive  and  irrational  system  of  all, 
and  one  more  commonly  practiced  than  any  other  in 
general  farming,  may  be  termed  the  "hit  or  miss" 
system;  if  a  "hit"  is  made,  there  is  a  profit,  if  a 
"miss,"  the  loss  is  trifling.  In  this  system,  no  special 
thought  is  given  to  the   character  of   the  crop  or   its 


190  FEBTILIZEBS 

needs.  If  the  farmer  can  afford  it,  he  purchases  a 
fertilizer,  without  regard  to  its  composition,  and  ap- 
plies it  in  very  small  amounts.  If  it  happens  to  con- 
tain that  element  which  is  particularly  needed  for  the 
plant  to  which  it  is  applied,  a  profit  is  secured.  In 
too  many  cases,  however,  the  constituents  added  are 
already  in  abundance  in  the  soil,  or  so  little  of  the 
fertilizer  is  used  as  to   preclude  any  profit. 

SUMMARY 

With  the  exception  of  this  last  system,  there  are 
good  features  in  all  of  these  suggested  methods  of  use, 
and  it  rests  with  the  farmer  to  select  the  best  points 
from  each,  or  rather  to  use  the  suggestions  in  each 
which  are  in  his  judgment  more  applicable  to  his  con- 
ditions. They  are  all  based  upon  underlying  principles, 
and  pre -suppose  a  knowledge  of  them  on  the  part  of 
the  farmer.  They  are,  at  best,  but  guides  or  sign -posts 
pointing  toward  better  methods  in  the  use  of  fertil- 
izers, rather  than  absolute  rules  to  be  blindly  followed. 

The  suggestions  here  and  in  subsequent  chapters, 
in  reference  to  the  use  of  fertilizers,  are  formulated 
from  the  best  information  obtainable  by  the  writer, 
and  mainly  from  two  sources :  Fii'st,  the  results  of 
experimental  inquiry,  and,  second,  the  results  of  the 
observation  and  experience  of  practical  men.  In  no 
case  can  absolute  rules  be  laid  down.  Farmers  may 
safely  rely  on  the  well-established  principles,  but  each 
must  remember  that  the  use  of  the  principles  must 
be  modified  according  to  his  own  conditions. 


CHAPTER    X 

FERTILIZERS   FOR    CEREALS  AND    GRASSES 

It  has  already  been  pointed  out  (p.  175)  that 
these  crops  are  classed  as  possessing  a  relatively  low 
commercial  value  and  a  relatively  high  fertility  value, 
and  that,  from  a  practical  standpoint,  in  any  fertiliza- 
tion of  them  a  possible  profitable  return  should  be 
borne  in  mind.  This  is,  of  course,  necessary  in  all 
cases,  but  is  particulary  necessary  where  an  increased 
yield,  as  great  as  can  be  expected  from  an  application 
of  proper  fertilizing  materials,  cannot  possibly  result 
in  an  extraordinary  profit,  a  result  quite  possible  with 
certain  crops  of  the  opposite  class.  The  possible  in- 
crease in  yield,  too  is,  dependent  on  the  conditions  of 
soil  and  season,  and  if  these  latter  are  such  as  to 
forbid  a  maximum  increased  yield,  the  immediate 
profits  from  the  application  are  considerably  reduced. 

It  has  been  shown,  too,  by  careful  experiments, 
that,  on  the  average,  at  least  one -third  of  the  nitro- 
gen applied  to  these  crops,  though  contained  in  the 
best  forms,  is  not  secured  in  the  crop,  even  under 
the  most  favorable  conditions ;  that  is,  in  any  case 
certain  amounts  are  lost  through  drainage,  the  growth 
of  weeds  and  denitrification ;  and,  further,  that  the 
minerals  must  exist  in  the  soil,  or  must  be  supplied 
in   sufficient    excess,  otherwise,  the   utilization   of   the 

(191) 


192  FERTILIZERS 

nitrogen  by  the  plant  is  still  further  reduced.  The 
expense  of  fertilizer  per  unit  of  increase  in  these 
crops  is,  therefore,  relatively  greater,  even  under  the 
best  conditions  of  its  use.  A  bushel  of  wheat,  with 
its  accompanying  straw,  will  contain,  for  example: 

Nitrogen 1%  lbs. 

Phosphoric  acid %    " 

Potash l>i    " 

It  will  be  observed  that  the  amounts  of  fertilizer 
ingredients  contained  in  the  crop  are  such  that,  if  the 
seasonal  conditions  are  perfect,  so  that  the  maximum 
of  the  amounts  applied  are  recovered  in  the  crop,  the 
cost  of  fertilizers  per  bushel  of  increase  is  still  rela- 
tively high,  thus  showing  that  great  care  must  be 
exercised  in  order  that  a  direct  and  immediate  profit 
may  be  secured.  Nevertheless,  since  the  cost  of  pre- 
paring the  land  and  of  harvesting  the  crop  is  but 
slightly  greater  for  a  large  crop  than  for  a  small  one, 
the  larger  returns  for  the  labor  very  frequently  pay 
well  for  the  application  of  the  material,  even  though 
the  margin  of  money  profit  is  small.  In  crops  of 
this  sort  therefore,  and  especially  when  grown  on 
the  "extensive"  plan,  an  important  point  to  be  de- 
termined is  whether  the  land  is  deficient  in  all  of 
the  constituents  for  grain  and  hay  growing,  or  whether 
only  one  or  two  are  lacking,  in  order  that  in  the  ap- 
plications made,  only  those  constituents  are  supplied 
that  are  necessary,  and  adding  to  an  excess  already 
present  is  thus  avoided,  with  a  consequent  saving  in 
the  cost  of  the  fertilizer. 


FARMERS    SHOULD    EXPERIMENT  193 

EXPERIMENTS    TO    DETERMINE    THE    LACKING 
ELEMENT 

The  lacking  element  cannot  be  fully  determined, 
except  by  direct  experiments  by  the  farmer  himself. 
That  is,  no  general  principle  can  be  depended  on 
as  an  absolute  guide.  He  should  learn  whether  his 
soil  is  deficient  in  any  of  the  elements,  and,  if  so, 
which  ones  should  be  applied  to  the  different  crops 
in  his  rotation.  A  careful  study  along  this  line,  too, 
will  show  whether  it  is  fertilization  that  is  required 
to  meet  seeming  deficiencies,  for  it  frequently  hap- 
pens that  the  needs  of  the  soil  are  not  so  much  for 
added  plant -food  as  for  better  management  of  the 
soil  in  other  respects,  in  order  that  natural  supplies 
may  be  made  more  available. 

It  may  seem,  at  first  glance,  that  experimenting 
should  be  left  to  the  experiment  stations,  and  that 
farmers  should  be  advised  by  them  in  respect  to  the 
needs  of  their  soils  in  respect  to  plant -food.  This 
is  partly  true,  but  the  proper  function  of  experiment 
stations  is  to  establish  principles,  the  application  of 
which  must  be  left,  in  large  part  at  least,  to  the 
intelligence  of  those  who  are  to  utilize  them.  The 
farmer  must  study  his  own  conditions.  Scientific  in- 
quiry has  established  the  facts  that  soils  differ  in  their 
content  of  the  different  plant -food  elements,  and  that 
those  of  practically  the  same  chemical  composition 
differ  in  respect  to  their  physical  qualities,  both  of 
which  conditions  exercise  an  important  influence  upon 
the  availability  of  the  constituents. 

M 


194  FERTILIZERS 

This  experimenting  may  also  seem  to  be  a  trouble- 
some operation,  yet,  if  thoughtfully  managed,  it  will 
mean  but  little  extra  labor,  and  the  resulting  gain 
may  be  far  in  excess  of  the  cost  of  the  work.  For 
example,  if  it  is  shown  that  fertilization  under  certain 
conditions  is  not  the  thing  needed,  and,  therefore,  not 
profitable,  it  saves  possible  outlay  at  once;  if  it  shows 
that  the  application  of  certain  of  the  constituents  is 
a  profitable  practice,  it  enables  the  adoption  of  a 
systematic   scheme   of    fertilization. 

A    Scheme  for   Plot    Experiments 

The  following  simple  scheme  of  plot  experimenting 
has  been  suggested,  and  it  admits  of  determining 
many  of  the  points  involved.  This  scheme  includes 
ten  plots,  in  which  three  are  to  be  cropped  without 
manure,  as  check  plots,  in  order  to  show  the  produc- 
tive capacity  of  the  unmanured  land.  The  plots  may 
vary  in  size,  though  it  is  desirable  that  they  should 
contain  at  least  one -twentieth  of  an  acre,  and  that 
they  should  be  long  and  narrow,  in  order  to  include 
as  many  inequalities  of  the  soil  as  possible,  though 
in  any  case  land  as  uniform  as  possible  in  physical 
and  chemical  qualities,  and  fairly  representative, 
should  be  selected.  The  following  plan  permits  of  a 
study  of  the  effect  of  the  application  of  individual 
constituents,  and  of  their  various  combinations.  If 
desired,  in  order  to  simplify  the  work  in  the  begin- 
ning, only  the  first  four  plots  need  be  taken.  This 
will  reduce  the  labor,   and,   at  the  same  time,  permit 


PLAN   OF  EXPEBIMENTS  195 

a  study  of  the  soil's  deficiencies  in  respect  to  single 
elements  of  plant -food,  and  the  relative  needs  of 
the  different  crops  for  the  various  constituents. 

Plan   of   Experiments  —  Size   of   Plots,   -^  of   an   Acre 

Plot  I.  Cheek.     No  fertilizer. 

II.  Nitrate  of  soda 8  lbs. 

III.  Superphosphate 16  " 

IV.  Muriate  of  potash 8  " 

V.  Check.     No  fertilizer. 

VI.  Nitrate  of  soda,  20  lbs.  Superphosphate.  16  " 

VII.  Nitrate  of  soda,  20    "     Potash 8  " 

VIII.  Phoshoric  acid,  40    "     Potash 8  " 

IX.  Nitrate  of  soda,    8    "     Superphosphate,  16  " 

Potash 8    " 

"     X.        Check.     No  fertilizer. 

The  rate  of  application  per  acre  is  greater  than 
would  naturally  obtain  in  practice,  in  order  both  to 
facilitate  the  distribution  of  the  fertilizer,  to  furnish 
a  sufficient  abundance  of  the  constituent,  and  to  pro- 
vide against  unfavorable  conditions. 

Preferably,  the  application  should  be  made  broad- 
cast, and  before  planting,  if  an  ^ncultivable  crop, 
though  for  cultivable  crops  it  may  be  applied  later 
and  harrowed  in. 

It  will  be  observed  that  the  amounts  of  fertilizer 
are  one  pound  per  square  rod,  or  multiple  thereof. 
Thus,  in  order  to  insure  an  equal  distribution  over 
the  entire  area,  it  may  be  roughly  divided  into  plots 
of  a  square  rod,  and  the  required  material  for  each 
rod  applied  separately.  Careful  weights  should  be 
made   of  the  yields  of   the  different  plots,   as  a  basis 


196  FERTILIZERS 

of  comparison.  The  same  fertilizers  should  be  used 
on  the  different  crops  of  the  rotations,  and,  as  inter- 
est is  increased  in  the  work,  different  forms  and 
amounts  of  the  various  constituents  may  be  intro- 
duced. 

Results  That  May  Be  Attained 

If  it  is  found  that  for  a  certain  crop  only  one  of 
the  applied  constituents  profitably  increases  the  yield, 
then  that  should  be  used  until  the  need  of  the  others 
is  apparent.  If  two  are  needed  to  accomplish  the 
results,  use  two,  and  so  on;  though  in  the  long  run, 
or  as  the  practice  approaches  the  "intensive"  system, 
all  will  doubtless  be  required.  In  "extensive"  farming 
this  is  a  very  desirable  line  of  experimentation,  and 
can  be  carried  out  by  individual  farmers.  It  is  useful 
not  only  in  showing  the  deficiencies  of  the  soil  for 
the  various  crops,  but  is  educative  in  its  character,  as 
it  familiarizes  the  farmer  with  the  materials  that  are 
used  in  making  fertilizers,  and  encourages  exact 
methods  of  work..  Since,  as  already  stated,  the  need 
very  frequently  is  not  so  much  for  added  fertilit}^  as 
it  is  for  better  preparation  and  cultivation  of  the  soil, 
or  for  amendments  such  as  lime,  it  would  be  a  desir- 
able practice  to  include  in  the  number  of  plots  here 
indicated  one  or  two  in  which  the  cultivation  of  the 
soil  was  made  more  perfect,  in  order  to  determine 
whether  the  need  is  for  more  fertility  elements  or 
whether  it  is  for  better  tillage,  the  effect  of  which 
is  to  render  more  of  the  soil  constituents  available  to 


THE  RESULTS   OF  EXPERIMENTS  197 

the  plant.  One  or  two  to  which  lime  is  added  may 
be  advisable,  in  order  to  determine  whether  this  sub- 
stance is  needed  either  to  correct  acidity  or  to  make 
available  otherwise  unusable  compounds.  This  method, 
while  particularly  desirable  where  "  extensive  "  methods 
of  practice  prevail,  is  of  less  importance  where  the  aim 
is  to  grow  maximum  crops,  in  which  case  both  the 
crop  and  its  rotation  are  to  be  considered,  and  the 
needs  of  the  plant  rather  than  the  deficiencies  of 
the  soil   require  first   attention. 

The  results  of  experiments  which  have  been  con- 
ducted with  great  care  in  a  number  of  states  show 
that  where  "extensive"  methods  are  practiced  certain 
elements  need  not  be  added  in  the  fertilizers;  that 
is,  that  the  soil  contains  such  an  abundance  of  them 
that  the  plant  is  able  to  obtain  a  full  supply,  at  least, 
for  a  long  time.  For  example,  it  has  been  shown 
that  on  the  chief  sugar -producing  soils  of  Louisiana 
and  Mississippi,  and  the  cotton  soils  of  Georgia  and 
Texas,  the  addition  of  potash  has  been  of  less  im- 
portance in  the  past  than  the  other  elements,  and  it 
frequently  does  not  need  to  be  included  in  the  fer- 
tilizer, while   phosphoric  acid   is  always  needed. 

The  results  of  field  experiments  on  this  plan  in 
New  Jersey,  on  reasonably  good,  loamy  soils,  indi- 
cate that  phosphoric  acid  and  potash  are  of  much 
more  importance  in  fertilizers  for  corn  than  nitro- 
gen, whereas  upon  sandy  soils,  nitrogen  and  potash 
are  of  relatively  more  importance  than  phosphoric 
acid;  that  is,  even  where  "extensive"  practice  is  used 
there   are  conditions  where   one   or   more   of    the   ele- 


198  FERTILIZERS 

ments  are  not  required  iu  order  to  secure  maximum 
crops,  which  eliminates  the  necessity  for  an  imme- 
diate outlay  for  those  constituents  that  are  not 
lacking.  Where  experiments  of  this  sort  have  not 
been  carried  out  and  the  specific  needs  determined,  it 
becomes  necessary  to  assume  that  all  of  the  constituents 
are  required,  and  to  apply  the  amounts  and  propor- 
tions of  those  which  the  general  considerations  of  the 
soil,  season,  climate  and  crop  would  seem  to  demand. 

As  already  pointed  out,  the  methods  of  fertilization 
here  suggested,  though  in  many  instances  apparently 
positive,  are  not  to  be  interpreted  as  absolute  rules,  but 
rather  used  as  guides,  based  upon  the  best  information 
that  it  has  been  possible  to  obtain,  both  as  a  result 
of  scientific  inquiry  and  of  practical  experience. 

THE    IMPOBTANCE    OF    SYSTEM    IX    THE    USE    OF 
FERTILIZERS 

The  following  rotation  is  assumed,  in  order  to  show 
the  necessity  of  a  definite  system  of  work,  which  is 
quite  as  important  in  this  branch  of  farming  as  in 
many  others  in  which  system  is  apparently  more 
essential, — though  in  fact  it  is  quite  as  necessary  to 
observe  a  definite  system  in  the  feeding  of  plants  as 
in  the  feeding  of  animals  with  the  plants  : 

* 

Illustration  of  a  Rotation 

First  year Maize  (com) . 

Second  year Oats. 

Third  year Wheat. 

Fourth  year Clover  and  timothy 

Fifth  year Timothy  hay. 


SYSTEMATIC   FERTILIZATION  199 

Indian   Corn  Exhaustive  of  the  Fertility  Elements 

Since  in  rotations  of  this  sort  a  fair  number  of  live 
stock  is  usually  kept,  a  considerable  amount  of  ma- 
nure is  made,  which  should  be  carefully  cared  for  and 
used,  as  it  contributes  materially  to  the  success  of  the 
plan.  The  manure  may  be  used  in  part  on  land  for 
corn,  and  should  be  spread  broadcast,  practically  as 
fast  as  made  during  the  fall,  winter  and  early  spring. 
This  plant,  because  it  is  a  gross  feeder,  and  also 
because  it  makes  most  of  its  growth  during  the  sum- 
mer season,  when  activities  in  the  soil  are  most  rapid, 
is  able  to  appropriate  from  the  coarse  manures  a  larger 
proportion  of  the  constituents  than  would  be  possible 
for  crops  which  make  their  greatest  growth  earlier  or 
later  in  the  season.  In  the  summer,  too,  the  condi- 
tions are  most  favorable  for  nitrification,  and  soils 
which  possess  a  fair  content  of  vegetable  matter  are 
usually  able  to  furnish  the  nitrogen  needed  in  addition 
to  that  supplied  in  the  organic  manures,  particularly 
in  the  middle  and  southern  states.  The  considerable 
amounts  of  potash  required  for  the  growth  of  stalks, 
and  the  phosphoric  acid  for  the  formation  of  grain, 
demand  that  a  liberal  supply  of  these  constituents  be 
provided,  and  the  fertilizer  for  the  corn  should,  there- 
fore, contain  an  abundance  of  available  phosphoric 
acid  and  of  potash. 

A  crop  of  50  bushels  of  shelled  corn  per  acre,  with 
the  accompanying  stalks,  will  remove,  on  the  average, 
80  pounds  of  nitrogen,  29  pounds  of  phosphoric  acid, 
and  55  of  potash.     It  is  an  exhaustive  crop.     A  fer- 


200  FEBTILIZEBS 

tilizer,  therefore,  that  would  furnish  30  pounds  of 
phosphoric  acid  and  40  of  potash  would  be  regarded 
as  a  fair  dressing  for  land  of  medium  quality.  A  part 
of  the  phosphoric  acid,  at  least,  should  be  in  a  soluble 
form,  in  order  to  supply  the  early  needs  of  the  crop. 
The  remainder  may  consist  of  ground  bone  or  tankage, 
if  the  phosphoric  acid  in  these  can  be  obtained  more 
cheaply,  since  they  will  decay  rapidly  enough  to  supply 
the  demands  for  the  later  growth.  The  potash  may  be 
either  muriate  of  potash  or  kainit,  though  the  former 
is  preferable  if  it  is  applied  in  the  drill,  which  is,  if 
used  in  these  amounts,  a  perfectly  safe  practice  so  far 
as  injury  to  the  plant  is  concerned;  though  fertilizers 
containing  large  amounts  of  potash  salts  are  preferably- 
applied  broadcast  on  raw  ground  of  a  clayey  nature, 
and  well  worked  into  the  soil,  thus  insuring  a  good 
distribution.  The  cost  of  an  application  of  this  sort 
will  be  relatively  small,  and  the  minerals  added  will  be 
more  than  sufficient  to  provide  for  a  considerable 
increase  in  crop.  If  the  land  is  light  and  sandy, 
nitrogen  should  be  added,  even  though  it  has  received 
a  good  dressing  of  yard  manure,  as  these  lands  are 
usually  deficient  in  this  element,  and  organic  forms  are 
usually  quite  as  useful  as  the  soluble  nitrate  or 
ammonia,  since  the  seasonal  conditions  during  the 
period  of  growth  are  favorable  for  the  rapid  change  of 
the  nitrogen  in  materials  of  good  quality,  like  blood, 
concentrated  tankage,  or  cotton -seed  meal,  into  nitrates. 
The  amounts  of  nitrogen  needed  would,  under  ordinary 
conditions,  be  supplied  by  100  pounds  of  high-grade 
blood,  or  200  pounds  of  cotton -seed  meal.     The  nitro- 


FERTILIZERS  FOR   CEREALS  201 

gen  may  also  be  obtained  by  substituting  tankage  for 
the  superphosphate,  though  it  is  not  so  desirable  a 
practice. 

In  this  matter  of  fertilizing,  it  must  be  remembered 
that  weeds  appropriate  plant -food  quite  as  readily  as 
the  corn,  wherefore  in  order  to  obtain  the  best  results 
from  the  fertilizers  added,  clean  cultivation  should  be 
practiced. 

Oats 

For  the  oat  crop  that  follows  corn,  and  which  makes 
its  best  growth  early  in  the  season,  before  nitrification 
is  rapid,  quickly  available  forms  of  nitrogen  are  very 
desirable  ;  and  inasmuch  as  the  oats  require  an  abun- 
dance of  phosphates,  a  fertilization  with  phosphoric 
acid  is  also  essential.  Hence,  fertilizers  consisting  of 
mixtures  of  nitrate  of  soda  and  superphosphates  have 
proved  of  great  value  for  this  crop.  If  mixed  at 
home,  they  should  be  applied  immediately  after  prepa- 
ration, for  a  loss  of  nitrogen  may  result  if  the  mix- 
ture is  allowed  to  stand  for  any  length  of  time.  An 
application  of  8  pounds  of  nitrogen  and  18  of  phos- 
phoric acid,  or  200  pounds  per  acre  of  a  mixture  of  50 
pounds  of  nitrate  of  soda  and  150  of  acid  phosphate, 
has  proved  quite  as  profitable  on  medium  soils  as 
heavier  applications,  mainly  because  the  oat  crop  is 
a  less  certain  one  than  corn ;  besides,  it  frequently 
suffers  severe  losses  in  harvesting,  which  increase  the 
risk  from  an  expensive  fertilization.  The  application 
of  potash  is  not  so  necessary  if  added  in  the  fertil- 
izer for  corn,  as  suggested,  except  on  light,  sandy  soils. 


202  FERTILIZEB8 

Wheat 

For  the  wheat  crop  following  oats,  the  rest  of  the 
farm  manure  on  hand  may  be  applied  after  plowing, 
well  harrowed  into  the  surface  soil,  and  a  fertilizer  ap- 
plied which  shall  be  rich  in  available  phosphoric  acid, 
and  which  shall  contain  only  a  sufficient  amount  of 
nitrogen  in  quickly  available  forms  to  insure  a  good 
fall  growth.  When  the  land  has  been  well  fertilized 
for  previous  crops,  a  dissolved  animal  bone  super- 
phosphate is  an  excellent  fertilizer  for  wheat,  because 
containing  the  elements,  phosphoric  acid  and  nitrogen, 
in  good  forms  and  proportions.  If  more  nitrogen  is 
needed  than  is  provided  by  200  to  300  pounds  of  this 
fertilizer  in  order  to  mature  the  crop,  which  is  fre- 
quently the  case,  particularly  if  the  winter  has  been 
severe,  or  if  the  land  is  light,  it  may  be  applied  in  the 
spring,  and  preferably  in  the  form  of  a  nitrate,  which 
distributes  readily,  and  is  immediately  available,  ad- 
vantages not  possessed  by  other  forms.  At  this  period 
of  its  growth,  the  crops  need  to  make  a  rapid  appro- 
priation of  nitrogenous  food,  though  the  conditions  are 
not  yet  favorable  for  the  change  of  nitrogenous  organic 
compounds  in  the  soil  into  the  available  nitrate.  The 
top -dressings  should  be  made  as  soon  as  the  crop  has 
been  well  started,  and  should  range  from  75  to  150 
pounds  per  acre,  according  to  the  character  of  the 
soil  and  previous  fertilization.  The  better  the  natural 
character  of  the  soil  and  its  treatment,  the  larger  the 
dressing  that  may  be  applied  with  possible  profit, 
though  in  no  case  should  it  exceed  the  larger  amount. 


FEBTILIZEBS  FOB   CLOVEB  AND   TIMOTHY     203 

Clover 

For  the  clover  which  follows  the  wheat,  only  the 
minerals,  phosphoric  acid  and  potash,  need  be  applied. 
An  increased  return  is  likely  to  follow  such  an 
application,  as  the  clover  is  not  able  to  utilize  to  the 
fullest  extent  the  nitrogen  from  the  air  except  when  the 
soil  is  supplied  with  an  abundance  of  mineral  food. 
An  application  which  will  furnish  12  pounds  of  phos- 
phoric acid  and  25  pounds  of  potash  per  acre  marks 
the  minimum  dressing,  and  it  may  be  applied  with 
advantage  immediately  after  the  wheat  is  harvested. 

Timothy 

The  timothy,  the  next  crop  in  the  rotation,  is  a 
member  of  the  grass  family,  and  is  especially  benefited 
by  nitrogenous  fertilization,  and  top -dressings  in  the 
spring  with  nitrate  of  soda  have  proved  of  great  value 
on  soils  well  supplied  with  minerals,  though  experienced 
farmers  have  learned  that  better  results  are  obtained  if 
the  minerals  are  applied  with  the  nitrate,  thus  in- 
suring a  better  growth  and  development  of  plant.  A 
mixture  made  up  of  150  pounds  of  nitrate  of  soda, 
100  of  acid  phosphate  and  50  of  muriate  of  potash,  at 
the  rate  of  300  pounds  per  acre,  is  now  used  by  many 
successful  hay  growers.  The  application  should  be 
made  as  soon  as  the  crop  has  well  started  in  the 
spring. 

The  system  of  fertilization  here  outlined  is  not  to  be 
advocated  except  under  circumstances  where  it  is  not 


204  FEBTILIZEBS 

possible  or  practicable  to  supply  such  an  abundance  of 
plant -food  as  will  guarantee  a  maximum  production,  as 
in  "intensive"  practice,  in  which  the  yield  is  measured 
by  climatic  and  seasonal  rather  than  soil  conditions, 
but  rather  such  additions  as  will  return  a  profit  and  at 
the  same  time  tend  toward  the  improvement  of  soil. 
This  system  is  economical  in  the  use  of  nitrogen,  the 
most  expensive  element.  It  provides  a  sufficient 
amount  of  available  plant -food  to  insure  a  reasonable 
increase  in  crop,  and  it  is  well  adapted  to  lead  the 
farmer  by  easy  steps  from  the  "extensive"  to  the 
"intensive"  system  of  farming. 

A  Gain  of  Fertility  hy  the  Rotation  System 

Assuming  that  the  increased  yield  of  corn  is  20 
bushels,  with  accompanying  stalks,  of  wheat  10  bushels 
per  acre,  of  oats  15  bushels,  of  clover  %  ton,  and  of 
timothy  %  ton,  the  amounts  applied  will  be  practically 
sufficient  to  furnish  all  of  the  potash  contained  in  this 
increase,  and  more  than  sufficient  to  meet  the  demands 
for  phosphoric  acid.  That  is,  by  this  system,  there  has 
been  applied  in  the  materials  30  pounds  of  nitrogen, 
64  of  phosphoric  acid  and  80  of  potash.  While,  if 
this  increased  crop  was  secured,  the  following  amounts 
would  be  required :  71  pounds  of  nitrogen,  31  of 
phosphoric  acid  and  79  of  potash.  The  considerable 
amounts  of  plant -food  contained  in  the  yard  manure, 
and  the  gain  from  the  roots  and  stubble  of  the  clover, 
serve  to  supply  the  balance  of  nitrogen  required,  and 
to  provide  a  store  of  unused  residue  for  future  crops. 


NECESSITY  OF  AN  EXCESS   OF  FOOD  205 

The  method,  if  adopted,  would  be  more  rational,  and 
likely  to  result  in  more  satisfactory  returns  than  the 
one  now  generally  practiced,  namely,  to  purchase  with- 
out particular  regard  to  the  character  of  the  materials 
furnishing  the  constituents,  or  their  proportions,  and 
to  apply,  on  the  average,  even  less  per  acre  than  is 
here  recommended.  Assuming  that  200  pounds  per 
acre  of  the  average  corn  fertilizer,  showing  a  composi- 
tion of  2.5  per  cent  nitrogen,  8  of  phosphoric  acid  and 
5  of  potash,  were  applied  only  to  the  crops  corn,  oats 
and  wheat,  omitting  both  clover  and  timothy,  there 
would  have  been  added  15  pounds  of  nitrogen,  48  of 
phosphoric  acid  and  30  of  potash,  amounts  of  each  too 
small  to  provide  for  a  lai'ge  increase  in  crop,  provided 
all  were  needed. 

The  Necessity  of  Adding  More  Plant- food  than  is 
Required  hy  a  Definite  Increase  in  Crop 

It  may  be  asked,  why  add  more  of  the  constituents 
than  is  necessary  to  provide  for  a  definite  increase  in 
crop?  Assuming  that  the  average  yield  of  the  land 
is  twenty  bushels  of  wheat  per  acre,  and  the  aim  is 
to  secure  thirty  bushels,  why  not  add  the  constituents 
in  the  amounts  and  proportions  necessary  to  provide 
for  this  extra  increased  yield,  rather  than  any 
excess  of  these  amounts  ?  The  answer  is,  that  in 
order  that  such  a  result  may  be  accomplished,  the 
conditions  would  need  to  be  absolutely  perfect,  so 
that  the  plant  would  have  at  its  command  the  amount 
of  food  needed  each  day.     If  a  period  in  the  growth 


206  FERTILIZERS 

of  the  plant  should  be  so  wet  or  so  dry  as  to  prevent 
the  plants  from  acquiring  the  food  necessary  for  their 
continuous  growth,  there  would  be  no  opportunity  for 
them  to  gather  food  faster,  when  the  better  conditions 
followed  the  unfavorable  conditions,  and  thus  to  over- 
come the  ill  effects  of  the  period  of  partial  starvation. 
In  other  words,  if  there  were  only  sufficient  food  to 
supply  the  plant  under  normal  conditions  of  season, 
the  plant,  after  a  period  of  time  during  which  there  was 
no  growth,  could  not  grow  faster  than  it  did  before, 
hence  it  could  not  catch  up  in  its  growth  and  make  a 
full  crop.  Furthermore,  the  plan  of  applying  only 
that  needed  for  the  increase  must  necessarily  assume 
that  the  plant -food  is  in  the  best  forms,  and  that  the 
physical  conditions  of  soil  are  so  perfect  as  to  cause 
it  to  absorb  and  retain  all  the  food  applied,  and  in 
such  a  manner  as  to  permit  it  to  be  readily  obtained 
by  the  plant.  A  further  advantage  is  to  enable  the 
clover  plant  in  the  rotation  to  fully  exercise  its  power 
of  acquiring  nitrogen  from  the  air.  Moreover,  if 
properly  carried  out,  it  fulfils  the  idea  of  successful 
agriculture  ;  viz.,  the  production  of  profitable  crops, 
while  at  the  same  time  not  reducing,  but  increasing, 
the  potential  fertility  of  the  soil. 

The  System  Should  Be  Modified  if  no  Farm    Manures 
are    Used 

In  this  rotation,  if  no  manures  are  available,  as 
indicated,  then  the  amounts  and  kinds  of  fertilizers 
should  be  somewhat  changed.     For  example,  if  it  was 


I 


EXCLUSIVE   USE   OF  FEBTILIZEBS  207 

necessary  to  supply  the  corn  crop  with  a  sufficient 
abundance  of  all  the  elements  in  artificial  forms,  then 
the  proportions  of  nitrogen  should  be  somewhat  greater 
and  the  total  amounts  of  the  constituents  applied  to 
the  different  crops  considerably  increased.  For  corn,  a 
mixture  consisting  of  20  pounds  of  nitrogen,  30  of 
phosphoric  acid  and  50  of  potash  should  be  applied, 
and  if  grown  upon  raw  ground  rather  than  upon  sod, 
it  would  be  desirable  to  still  further  increase  the 
nitrogen.  The  oats  could  be  fertilized,  as  before  rec- 
ommended, while  the  wheat  should  have  an  increased 
supply  of  both  nitrogen  and  phosphoric  acid, — double 
the  amounts  recommended  when  used  with  manure, — 
besides  an  addition  of  at  least  10  pounds  per  acre  of 
potash.  The  fertilizing  of  the  clover  and  timothy  need 
not  be  changed.  If,  in  a  rotation  of  this  character, 
barley  were  substituted  for  oats  and  rye  for  wheat,  the 
fertilization  need  not  be  materially  changed,  though  the 
rye  possesses  a  slightly  greater  power  of  acquiring 
phosphoric  acid  than  wheat,  and  the  nitrogenous  top- 
dressings  may  be  omitted,  unless  the  crop  is  grown 
primarily  for  straw  rather  than  for  grain.  The  barley 
is  also  less  able  to  acquire  its  phosphoric  acid  than 
the  oats,  and  is  especially  benefited  by  nitrogen,  though 
care  should  be  exercised  to  regulate  the  amounts  ap- 
plied in  order  to  prevent  lodging,  which  affects  both 
the  yield  and  quality  of  the  grain.  If  in  the  rota- 
tion the  timothy  hay  is  omitted,  then  the  fertilization 
for  the  com  may  be  reduced,  as  on  good  soils  the 
yard  manure,  together  with  the  plant-food  stored  in 
the  surface  in  the  clover  sod,  will  furnish  an  abundance. 


208  FERTILIZERS 

FERTILIZERS    FOR    A    SINGLE    CROP    GROWN 
CONTINUOUSLY 

When  it  is  desirable  to  grow  any  one  or  all  of 
these  crops  continuously  (and  this  practice  may  be 
followed  with  advantage,  particularly  when  a  legumi- 
nous catch -crop  is  seeded  with  the  main  crop,  which 
insures  a  continuous  occupation  of  the  land  and  also 
provides  vegetable  matter  and  nitrogen),  the  fertiliza- 
tion would  naturally  be  somewhat  different,  and,  as  a 
rule,  would  require  more  nearly  even  quantities  of  the 
different  constituents.  For  corn,  a  fertilizer  supplying 
20  pounds  of  nitrogen,  40  each  of  phosphoric  acid  and 
potash,  would  provide  for  a  liberal  increase  in  the 
yield  from  year  to  year.  The  nitrogen  should  prefera- 
bly be  in  good  organic  forms,  which  would  decay  rap- 
idly enough  to  supply  the  needed  available  nitrogen 
during  the  growing  season.  The  phosphoric  acid  may 
be  drawn  partly  from  superphosphates  and  partly  from 
organic  compounds,  as  gi'ound  bone  and  tankage,  pro- 
vided these  latter  may  be  secured  at  as  low  a  price  as 
the  superphosphate,  and  the  potash  applied  in  the 
form  of  a  muriate  or  kainit.  Fertilizers  may  be  applied 
broadcast  and  well  harrowed  into  the  soil,  or  part  may 
be  distributed  in  the  row  at  time  of  planting. 

If  a  catch  crop  were  seeded  to  be  used  as  green 
manure,  as,  for  example,  crimson  clover,  the  applica- 
tion of  nitrogen  may  be  very  materiallj^  reduced.  This 
practice  has  been  followed  with  advantage  in  the  middle 
and  southern  states. 

For  continuous  wheat  growing,  a  fertilizer  may  be 


FERTILIZERS  FOR  A    CONTINUOUS   CROP       209 

used  at  time  of  seeding  which  supplies  10  pounds  of 
nitrogen,  40  of  phosphoric  acid  and  20  of  potash.  A 
small  part  of  this  nitrogen  would  better  be  in  the  form 
of  a  nitrate,  which  will  encourage  a  good  top -growth 
in  the  fall,  as  well  as  a  deep  root  system  ;  the  phos- 
phoric acid  should  be  soluble,  in  order  to  supply  the 
immediate  needs  of  the  young  plant,  and  the  potash 
in  the  form  of  a  muriate.  Such  an  application  would 
provide  for  a  very  considerable  increase  in  crop,  par- 
ticularly if  followed  in  the  spring  by  a  top-dressing  of 
100  pounds  per  acre  of  nitrate  of  soda. 

The  top-dressing  with  nitrate  of  soda  is,  however, 
not  always  advisable.  The  chief  objection  to  its  use  is 
that  it  does  not  encourage,  but  frequently  seems  to 
retard,  the  growth  of  clover,  though  its  very  great 
advantage  is  that  it  encourages  the  deeper  rooting  of 
the  wheat  and  the  more  rapid  growth  of  grasses.  If 
continuous  cropping  of  wheat  is  practiced,  clover 
should  be  seeded  with  it,  in  order  that  the  ground 
may  be  constantly  occupied,  and  thus  prevent  leaching, 
as  well  as  mechanical  losses  of  fertility,  and  also  to 
supply  vegetable  matter  containing  nitrogen  for  the 
succeeding  crop.  When  a  system  thus  outlined  has 
been  continued  for  a  few  years,  the  nitrogen  in  the 
fertilizer  may  be  largely  omitted. 

The  same  considerations  apply  to  rye  as  were  in- 
dicated for  wheat.  Oats  are  seldom  grown  as  a 
continuous  crop,  though  if  it  should  be  desirable,  a 
fertilizer  furnishing  at  least  20  pounds  of  nitrogen, 
25  of  phosphoric  acid  and  10  of  potash  would  be  a 
good  dressing,   care  being  taken  that  a  large  portion 

N 


210  FERTILIZERS 

of  the  nitrogen  exists  as  nitrate  or  as  ammonia,  in 
order  to  stimulate  and  strengthen  the  early  growth  of 
the  plant.  For  the  grass  crop,  or  continuous  mowing 
land,  a  fertilizer  rich  in  nitrogen  and  potash  should  be 
applied.  A  good  application  in  the  spring  may  consist 
of  25  pounds  of  nitrogen,  15  of  phosphoric  acid  and 
25  of  potash,  and  immediately  after  the  hay  is  har- 
vested a  further  application  of  at  least  20  pounds  of 
nitrogen  and  30  each  of  phosphoric  acid  and  potash 
should  be  applied.  The  nitrogen  in  this  case  may 
consist  partly  of  organic  forms,  though  the  soluble 
nitrogen  is  to  be  preferred  as  top -dressings  where  it 
can  be  procured  at  such  a  price  as  to  make  it  compara- 
ble with  other  forms.  The  nitrogen  of  bone,  tankage 
and  other  slower -acting  forms  is  excellent  for  the 
grasses,  though  these  should  be  preferably  applied  and 
well  worked  into  the  soil  previous  to  seeding.  The 
early  spring  application  should  consist  largely  of  solu- 
ble nitrogen,  both  to  encourage  a  rapid  appropriation 
of  this  element  by  the  plant  early  in  the  season,  as 
well  as  a  deeper  root- system,  and  consequently  a 
greater  drought -resisting  power,  and  also  to  provide  the 
elements  necessary  for  the  increased  crop.  The  sum- 
mer or  later  application  stimulates  and  strengthens  the 
roots  for  the  coming  season.  If  an  aftermath  crop  is 
removed,  or  if  it  is  pastured,  a  further  application 
may  be  made,  which  may  consist  largely  of  the  mineral 
elements.  This  fertilization  of  the  hay  crop  will  also 
result  in  a  richer  product,  for  an  abundant  supply  of 
nitrogen  encourages  a  larger  proportion  of  leaf  growth, 
and  consequently  a  smaller  proportion  of  stem,  contain- 


FERTILIZERS  FOB  MEADOWS  211 

ing  the  less  valuable  woody  matter.  Lands  that  are 
well  fertilized  in  this  way,  if  properly  seeded  in  the 
first  place,  may  make  profitable  mowing  crops  for  a 
long  series  of  years,  and  good  crops  cannot  be  expected 
unless  liberal  fertilization  is  practiced. 

Fertilizers  for  Meadows 

For  meadows  used  as  pastures,  a  more  liberal 
application  of  the  mineral  elements  is  recommended, 
since  an  abundance  of  these  encourage  the  growth  of 
the  clovers,  which  make  a  richer  herbage  than  the 
grasses.  Heavy  nitrogenous  fertilization  is  expensive, 
and  encourages  the  growth  of  the  grasses  rather  than 
the  clovers.  Pasturing,  while  less  exhaustive  than 
hay  cropping,  nevertheless  results  in  the  gradual 
depletion  of  fertility,  and  an  abundant  growth  of 
rich  pasturage  can  only  be  secured  where  there  is  an 
abundant  supply  of  available  plant -food.  Mixtures 
made  up  of  acid  phosphate,  ground  bone  and  muriate 
of  potash  in  equal  proportions,  make  very  good 
dressings,  if  applied  in  suflQcient  quantity,  three  hun- 
dred to  five  hundred  pounds  per  acre  annually.  The 
ground  bone  is  recommended  because  it  decays 
slowly,  and  thus  furnishes  a  continuous  supply  of 
nitrogen  and  of  phosphoric  acid.  The  application 
should  preferably  be  made  both  in  spring  and  in  late 
summer,  in  order  to  secure  a  good  growth,  as  well  as 
to  encourage  the  introduction  of  the  clovers.  In  any 
system  of  continuous  cropping,  or  in  fact  in  any  sys- 
tem of  rotation -cropping,   in  which  an   abundance  of 


212  FERTILIZERS 

organic  matter  is  introduced  in  the  way  of  green 
crops,  or  in  decaying  vegetable  matter  contained  in 
roots,  the  land  should  occasionally  receive  a  dressing 
of  lime,  both  to  supply  that  which  the  plants  need, 
as  well  as  to  correct  possible  acidity  of  soil. 

WILL    THIS    SYSTEM    of  FERTILIZING    PAY  ? 

That  fertilization  will  pay  if  carried  out,  as  is 
pointed  out  here,  and  upon  lands  not  now  producing 
paying  crops,  depends,  of  course,  very  largely  upon 
the  price  of  the  crops,  the  cost  of  the  materials,  and 
the  method  of  farming  practiced.  At  the  prices  which 
have  prevailed  in  the  recent  past,  for  both  crops  and 
fertilizing  materials,  there  is  no  doubt  that  this 
reasonable  fertilization,  together  with  a  good  system 
of  practice  in  other  respects, — that,  is,  good  plowing 
good  harrowing,  good  drainage  and  good  cultivation, 
— will  result  in  very  satisfactory  returns.  In  fact,  it 
has  been  shown  by  repeated  experiments  (see  bulletins 
and  reports  of  New  Jersey  Experiment  Station)  that 
the  yields  on  land  which  is  capable  of  producing  an 
average  crop  of  15  bushels  of  wheat  per  acre,  30  of 
corn  and  30  of  oats,  may  be  more  than  doubled  by 
an  abundant  supply  of  fertilizing  materials.  Such  an 
increase  results  in  an  actual  direct  gain,  as  well  as 
in  the  saving  of  labor  per  unit  of  product,  which  is 
accomplished  when  the  larger  crop  is  secured. 

The  main  point  in  this  whole  matter  of  fertiliza- 
tion is  to  understand  that  a  fertilizer  is  a  fertilizer 
because  of  the  kind  and  form  of  plant -food  contained 


WILL  FERTILIZING  PAT?  213 

in  it ;  and  that  its  best  action,  other  things  being 
equal,  is  accomplished  when  the  soil  possesses  good 
physical  qualities,  when  the  management  is  also 
good,  and  when  systematic  methods  are  planned  and 
adopted.  "Hit  or  miss"  fertilization,  even  for  these 
crops,  may  pay,  and  doubtless,  on  the  average  does 
pay  as  well  as  some  other  things  that  farmers  do,  but 
does  not  pay  as  well  as  it  might  if  better  methods 
were  used. 


CHAPTER  XI 

POTATOES,      SWEET     POTATOES,     TOMATOES     AND 
SUGAR  BEETS 

These  crops  differ  from  the  cereals  and  grasses  in 
that  they  are  products  of  high  commercial  value,  and 
are  less  exhaustive  of  plant -food  constituents  per  unit 
of  money  value.  As  field  crops  they  are  usually  grown 
in  a  rotation,  and  constitute  one  at  least  of  the  chief 
money  crops.  In  sections  near  large  markets  these 
crops  are,  with  the  exception  of  sugar  beets,  divided 
into  two  classes,  early  and  late,  the  early  crop  being 
regarded  as  the  most  profitable  ;  hence  greater  efforts 
are  made,  both  in  the  way  of  fertilization  and  of 
management,  to  secure  a  large  and  early  crop,  than 
is  the  case  with  the  late  crop.  For  the  early  crop 
the  natural  supply  of  plant -food  in  the  soil  is  not  a 
prime  consideration.  In  districts  distant  from  markets, 
the  late  crop  is  the  only  one  grown  to  any  extent,  and 
because  it  has  the  whole  season  for  its  growth,  greater 
dependence  is  placed  upon  the  natural  resources  of  the 
soil.  While,  as  already  stated,  these  crops  are  not 
regarded  as  exhaustive  of  plant -food  elements  in  the 
same  sense  as  the  cereal  crops  are,  because  it  fre- 
quently happens  that  a  bushel  of  potatoes,  or  of  sweet 
potatoes,  or  of  tomatoes,  will  bring  as  much  as  a 
bushel   of   corn,  or  sometimes  as   a   bushel   of  wheat, 

(214) 


FEBTILIZEB8  FOB  POTATOES  215 

yet  the  amount  removed  in  the  entire  crop  may  be 
quite  as  great  as  in  the  grain  crop,  because  of  the 
much  larger  number  of  bushels   grown   per  acre. 

FERTILIZERS  FOR  POTATOES,  EARLY  CROP 

It  has  been  demonstrated,  both  by  experiment  and 
practical  experience,  that  good  crops  of  early  potatoes 
require  an  abundance  of  plant -food,  and  that  on  soils 
of  good  character  a  heavy  fertilization  is  usually  more 
profitable  than  a  medium  or  light  application. 

The  plant -food  removed  by  a  fair  crop  —  200 
bushels  per  acre  of  tubers  —  will,  on  the  average, 
consist  of  27  pounds  of  nitrogen,  12  pounds  of 
phosphoric  acid  and  60  of  potash.  Even  though 
the  increase  from  the  application  of  fertilizers  is  less 
than  100  bushels  per  acre,  it  is  always  advisable 
to  add  plant -food  in  considerable  excess  of  these 
amounts :  first,  because  the  crop  must  be  grown 
quickly ;  and  second,  because  a  large  part  of  its 
growth  must  be  made  in  the  earlj^  season,  before  the 
natural  conditions  are  favorable  for  soil  activities. 
A  study  of  the  fertility  composition  of  the  potato 
shows  that  of  the  three  essential  constituents,  the 
potash  is  contained  in  the  greatest  amount  and  the 
nitrogen  next,  while  the  amount  of  phosphoric 
acid  contained  in  it  is  comparatively  small.  Most 
fertilizer  formulas  for  potatoes  are,  therefore,  pre- 
pared with  the  idea  of  furnishing  a  greater  amount 
of  potash  than  of  nitrogen  or  phosphoric  acid.  A 
study    recently    made    by    the     Geneva     Experiment 


« 
216  TERTILIZEBS 

Station*  shows  that  the  formulas  prepared  to  con- 
tain the  plant -food  in  nearly  the  proportions  used 
by  the  entire  potato  plant,  excepting  that  the  phos- 
phoric acid  is  in  considerable  excess,  were  less  useful 
than  those  containing  very  different  proportions 
of  the  constituents,  and  which  were  based  upon  the 
experience  of  observing  growers.  That  is,  a  formula 
of  the   first  class,  furnishing  — 

Nitrogen %%% 

Available  phosphoric  acid 5  % 

Potash Vd% 

gave  less  satisfactory  returns  for  the  same  amount 
applied  than  one  furnishing  — 

Nitrogen 4  % 

Available  phosphoric  acid 8  % 

Potash r 10  % 

This  latter  formula  is  very  generally  used  in  sections 
where  early  potatoes  are  an  important  crop. 

The  Time  and  Method  of  Application 

These  are  matters  of  considerable  importance. 
It  has  been  urged,  particularly  by  German  experi- 
menters, that  the  potash  salts,  when  used  in  such 
excess  as  seems  desirable,  should  be  applied  more 
largely  to  the  crop  preceding,  rather  than  directly  to 
the  potato  crop.  This  method  has  not  been  adopted 
in  this  country  to  any  extent,  and  it  is  believed  that 


♦  Bulletin  No.  137,  N.  Y.  State  Exp.  Sta. 


THE  AMOUNT  OF  FERTILIZER  217 

our  climatic  conditions  are  such  as  to  cause  a  very- 
general  distribution  of  the  salts  throughout  the  soil, 
if  applied,  in  part  at  least,  just  before  planting  and 
thoroughly  distributed  by  cultivation.  At  any  rate, 
very  satisfactory  returns  are  secured  from  the  direct 
application  to  the  crop  of  fertilizers  of  this  composi- 
tion. In  reference  to  the  method  of  application,  while 
very  good  results  are  secured  from  the  application  of 
the  fertilizers  directly  in  the  row,  this  is  to  some 
extent  influenced  by  the  character  of  the  soil.  Where 
the  soil  is  somewhat  heavy,  and  the  circulation  of 
water  is  not  perfectly  free,  it  is  less  desirable  than 
where  the  soils  are  open  and  porous,  and  free  circu- 
lation is  not  impeded ;  though  where  the  amounts 
applied  are  considerable,  it  is  recommended  that  at 
least  one -half  of  the  fertilizer  should  be  applied 
broadcast  and  worked  into  the  soil,  and  the  remainder 
placed  in  the  row  at  the  time  of  planting.  Naturally, 
when  the  soils  are  poor,  a  concentration  of  the  con- 
stituents is  more  desirable  than  when  the  surround- 
ing soil  possesses  reasonably  abundant  supplies  of 
available   food. 

The  Amount  to  he  Applied 

As  already  stated,  the  amount  of  the  different  con- 
stituents to  be  applied  should  be  in  considerable  excess 
of  that  required  by  the  actual  increase  in  crop,  both 
for  the  reasons  already  given,  and  because  it  is 
desirable  in  crops  of  this  sort  to  insure  a  continuous 
and  abundant  feeding  of  the  plant.     Where  "intensive" 


218  FERTILIZERS 

practice  is  general,  the  amounts  applied  very  frequently 
reach  a  ton  per  acre  of  the  high-grade  fertilizer 
already  mentioned,  though  the  necessity  for  so  large 
an  application  as  this  has  been  questioned,  particularly 
if  it  is  expected  to  give  rise  to  a  profitable  return  in 
the  crop  to  which  the  application  is  made,  and  though 
it  can  be  readily  seen  that  if  conditions  should  not  be 
favorable  the  larger  amounts  would  be  preferable.  The 
result  of  investigations  of  this  point  by  the  Geneva 
Experiment  Station*  showed  that  an  addition  of  fer- 
tilizers above  1,000  pounds  per  acre,  or  40  pounds  of 
nitrogen,  80  of  phosphoric  acid  and  100  of  potash, 
was  not  as  profitable  as  1,000  pounds.  It  must  be 
remembered,  however,  that  these  experiments  were 
conducted  upon  light  soils,  and  on  these  entire  de- 
pendence must  be  placed  upon  added  plant -food. 

In  the  best  potato  sections  of  New  Jersey,  the 
application  of  a  fertilizer  of  this  composition  ranges 
from  1,000  to  2,000  pounds  per  acre,  while  the  majority 
of  the  growers  use  the  smaller  rather  than  the  greater 
quantity.  Many  use  the  larger,  and  are  of  the  opinion 
that  it  is  a  profitable  practice,  because  of  the  greater 
certainty  of  securing  a  good  potato  crop,  and  because 
the  unused  residue  provides  for  large  yields  of  the 
subsequent  crop  without  further  applications.  The 
growers  of  potatoes  in  the  vicinity  of  Norfolk,  as 
well  as  farther  south,  also  find  it  profitable  to  be 
generous  in  the  use  of  fertilizer  for  this  as  well  as 
for  other  crops  of  high  commercial  value. 


♦BuUetins  93,  112,  137,  N.  Y.  State  Exp.  Sta. 


FERTILIZERS   SHOULD  BE  AVAILABLE  219 

Form  of  the  Constituents 

In  the  growing  of  potatoes,  sulfate  of  potash  is 
generally  recommended  in  preference  to  the  muriate, 
owing  to  the  supposedly  deleterious  effect  on  the 
quality  of  the  tubers  resulting  from  the  large  quantities 
of  chlorids  contained  in  the  muriate,  though  the  dif- 
ferent forms,  when  properly  applied,  do  not  seem  to 
materially  influence  the  yield.  That  is,  if  muriate  or 
kainit  is  applied  previous  to  the  planting  of  potatoes, 
the  deleterious  chlorids  may  be  washed  from  the  soil. 
There  is  no  doubt  that  the  sulfate  improves  the  ap- 
pearance of  the  potatoes,  making  them  more  clean  and 
uniform  in  size,  though  experiments  that  have  been 
conducted  do  not  show  a  material  difference  in  the 
chemical  composition  of  the  tubers  grown  with  any 
of  the  forms.  The  tendency  on  the  part  of  the  mu- 
riate seems  to  be  to  diminish  the  amount  of  dry 
matter,  and  inasmuch  as  the  dry  matter  is  mostly 
starch,  the  latter  is  thereby  slightly  reduced,  though  it 
has  not  yet  been  demonstrated  that  the  good  quality  of 
the  potatoes  is  measured  by  the  content  of  starch.* 

In  reference  to  the  form  of  nitrogen,  both  theoret- 
ical considerations  and  the  experience  of  growers  con- 
firm the  belief  that  for  the  early  crop,  a  portion  of 
the  nitrogen  should  exist  in  the  form  of  nitrate  or 
ammonia  and  the  remainder  in  quickly  available 
organic  forms,  although  no  definite  experiments  have 
been  conducted  to  determine  this   point,   nor  the   one 

♦BuUetin  No.  137,  N.  Y.  State  (Geneva)  Exp.  Sta.  Bulletin  No.  80,  N.J. 
Exp.  Sta. 


220  FERTILIZERS 

as  to  whether  all  of  the  nitrogen  in  the  form  of 
nitrate  should  be  applied  at  the  time  of  planting.  A 
top-dressing  after  the  potatoes  have  come  np  is  a  very 
desirable  method  of  practice  on  light  soils  which  have 
been  liberallj-  supplied  with  the  minerals. 

On  good  potato  soils,  therefore,  a  good  fertiliza- 
tion would  consist  of  800  pounds  per  acre,  as  a  mini- 
mum, of  a  mixture  containing : 

Nitrogen 3  to    4  % 

Phosphoric  acid 6  to    8  % 

Potash 8  to  10  % 

The  nitrogen  is  to  be  in  quickly  available  forms; 
the  phosphoric  acid,  also,  is  to  be  available,  and  the 
potash  to  be  derived  from  sulfate,  particularly  if  fine 
quality  of  crop,  as  indicated  by  appearance,  is  desired. 
If  only  yield  is  considered,  the  muriate  is  quite  as 
serviceable. 

LATE     POTATOES 

For  late  potatoes,  the  considerations  in  reference 
to  the  form  of  the  constituents  and  the  amount  of  the 
application,  as  suggested  for  early  potatoes,  do  not 
always  hold  good,  since  in  many  cases  the  crop  is  able 
to  secure  a  larger  proportion  of  its  plant -food  from 
soil  sources, — due,  first,  to  the  longer  period  of  growth 
of  the  plant,  and  second,  to  the  fact  that  the  crop  is 
usually  grown  upon  soils  naturally  richer  in  the 
plant-food  elements,  though  the  proportion  of  pot- 
ash, as  in  the  formulas  already  indicated,  should  be 
relatively  large.      The   nitrogen   may  be  reduced,  and 


FEBTILIZEBS  FOB  SWEET  POTATOES  221 

the  form  of  nitrogen  may  be  derived  largely  from 
organic  sources.  Good  formulas  for  late  potatoes 
may  consist  of  — 

Nitrogen 2%% 

Phosphoric  acid  • 6  % 

Potash 8  % 

and  the  application  may  be  from  600  to  800  pounds 
per  acre. 

Where  potatoes  are  grown  in  rotations  with  the 
cereal  crops  mentioned  in  Chapter  X,  the  unused 
residue  from  the  rather  heavy  application  of  fertil- 
izers to  the  potato  crop  is  depended  upon  to  very 
materially  aid  the  growth  of  these,  thus  reducing  the 
outlay  for  fertilizer  for  crops  of  a  low  commercial 
value.  This  practice  is  advantageous,  though  the 
prime  object  should  be  to  feed  the  crop  rather  than 
the  soil — that  is,  apply  the  fertilizer  with  the  idea  of 
securing  a  profit  from  it  in  the  potato  crop,  rather 
than  a    possible   profit    in  subsequent    crops. 

SWEET    POTATOES 

In  the  growing  of  sweet  potatoes,  the  quality  of 
the  product  is  more  important  than  in  the  case  of  the 
white  potato.  The  northern  markets  distinctly  recog- 
nize quality  in  this  crop,  and  it  is  measured  by  size, 
shape,  and  results  in  cooking.  The  potato  that  brings 
the  best  price  in  the  different  markets  is  small,  about 
the  size  of  a  white  potato;  in  shape  round,  rather 
than    oblong,    and    is    dry   and    mealy   when   cooked. 


222  FERTILIZERS 

This  characteristic  of  the  crop  is  influenced  both 
by  the  character  of  the  soil  and  of  the  manures  and 
fertilizers  applied.  The  soils  best  adapted  are  dry, 
sandy  loams,  and  the  most  useful  fertilizers  are  those 
which  contain  an  abundance  of  minerals, — phosphoric 
acid  and  potash, — and  not  too  large  supplies  of  quickly 
available  nitrogen.  It  is  also  true  that  the  yields  of 
sweet  potatoes  of  this  character  are  not  as  large  as 
those  that  may  be  obtained  when  quality  is  not  a 
prime  consideration,  and  which  are  grown  for  the 
general  market. 

Fertilizer  Constituents  Contained  in  an  Average  Crop 

This  crop  is  very  similar  to  the  white  potato  in 
regard  to  food  required.  Two  hundred  bushels  of 
sweet  potatoes,  not  including  vines,  contain,  on  the 
average,  30  pounds  of  nitrogen,  10  of  phosphoric  acid 
and  45  of  potash;  and  since  the  yield  of  the  general 
crop  is  larger  on  the  average  than  one  of  white 
potatoes,  a  liberal  supply  of  the  minerals  must  in 
all  eases  be  provided.  The  studies  made  of  this  crop 
have  not  yet  established  the  best  proportions  of  the 
constituents  in  fertilizers,  though  such  experiments 
as  have  been  conducted  show  that  those  that  contain 
a  very  considerable  excess  of  potash  over  the  other 
elements  are  preferable.  While  nitrogen  is  needed, 
too  much,  particularly  in  soluble  forms,  seems  to 
encourage  too  large  a  growth  of  vine,  which  con- 
tributes to  yield,  but  at  the  expense  of  quality,  which 
is  a  very  important  consideration.     The  best  growers 


PROFITABLE  FERTILIZATION  223 

use  fertilizers  contaiaiug  a  small  percentage  of  nitro- 
gen and  a  high  percentage  of  phosphoric  acid  and 
potash.  Applications  that  furnish  20  pounds  of  nitro- 
gen, 50  of  phosphoric  acid  and  80  of  potash  per  acre 
have  given  excellent  results  in  regions  in  New  Jersey 
in  which  market  quality  up  to  a  certain  point  is  quite 
as  important  as  increase  in  yield,  though,  of  course, 
yield  is  also  considered.  Any  excess  of  nitrogen  over 
this  amount  seems  to  contribute  toward  a  larger, 
rather  oblong,  rooty  growth  of  tuber,  and  to  injure 
cooking  quality.  In  growing  crops  for  the  general 
market,  however,  larger  applications  of  nitrogen  are 
demanded,  and  experiments  have  shown  that  organic 
forms  are  preferable  to  soluble  forms,  though  the 
climate  and  season  largely  influence  this  point.  In 
northern  sections,  and  in  cold  seasons,  the  soluble 
forms  are  more  useful  than  in  the  warmer  climate 
and   longer  seasons  of    the  South. 

There  is  no  question,  however,  that  commercial 
fertilizers  can  be  depended  upon  to  produce  maximum 
crops  of  sweet  potatoes,  and  at  much  smaller  cost 
than  with  yard  manure.*  Results  reported  by  the 
Georgia  Experiment  Station  t  indicate  the  following 
formula  as  an  excellent  one  for  sweet  potatoes, 
though,  as  there  stated,  "the  amounts  that  can  be 
used  vary  considerably,  depending  upon  the  character 
of  the  soil — the  richer  the  land  in  humus,  the  greater 
the  quantity  that  can  be  safely  used."  "Thin  soils 
will,  of   course,  only  stand  very  moderate   manuring, 

*  Bulletin  P,  New  Jersey  Exp.  Sta. 
t  Bulletin  No.  25,  Georgia  Exp.  Sta. 


224  FERTILIZERS 

and  necessarily  produce  a  very  small  yield."  The 
formula   consists   of  — 

Acid  phosphate 320  lbs. 

Cotton-seed  meal 360     " 

Kainit G40     " 

This  formula  will  furnish  about  25  pounds  of  nitro- 
gen, 50  of  phosphoric  acid  and  80  of  potash,  and, 
according  to  the  bulletin,  will  produce  a  yield  of 
potatoes  of  from  200  to  400  bushels  per  acre,  depend- 
ing upon  the  season  and  variety  of  potatoes  planted. 
Experiments  at  the  Georgia  Station  also  show  that 
organic  nitrogen  (cotton -seed  meal)  is  preferable  to 
nitrate  of  soda  as  a  source  of  nitrogen. 

In  making  mixtures  which  furnish  these  propor-' 
tions  of  plant -food,  other  nitrogenous  organic  ma- 
terials, furnishing,  an  equivalent  of  nitrogen, — as  blood 
or  concentrated  tankage, — may  be  substituted  for  the 
cotton -seed  meal,  if  they  can  be  purchased  quite  as 
cheaply;  and  muriate  of  potash,  furnishing  an  equiva- 
lent of  potash,  may  be  substituted  for  the  kainit,  if 
it  can  be  more  readily  obtained. 

As  already  stated,  however,  this  fertilizer  is  too 
rich  in  nitrogen  for  the  production  of  the  best  quality 
of  potatoes,  as  for  example  "Vineland  Sweets,"  which 
command  the  highest  prices  in  northern  markets.  The 
growers  in  that  district  use  a  fertilizer  richer  in  the 
minerals  ;    one  containing  — 

Nitrogen 3  % 

Phosphoric  acid 1  % 

Potash 12  %  - 


APPLICATION   OF   FERTILIZERS  225 

is  very  generally  used,  though  reasonably  heavy 
dressings  of  this  are  often  further  supplemented 
by  applications  of  from  200  to  300  pounds  of  acid 
phosphate  and  100  to  150  pounds  of  muriate  of 
potash   per  acre. 

The  Application  of  the  Fertilizers 

Owing  to  the  fact  that  the  sweet  potato  is  grown 
from  plants  or  slips,  rather  than  from  seed,  and  the 
fact  that  the  best  quality  of  potatoes  is  produced  upon 
rather  light,  sandy  land,  it  is  desirable  that  the  fer- 
tilizer should  be  applied  some  time  before  the  putting 
out  of  the  plants.  The  practice  on  this  light  land  is 
to  apply  the  fertilizer  when  making  up  the  hills,  which 
usually  occurs  from  two  to  three  weeks  before  the  plants 
are  set.  That  is,  in  making  up  the  hills,  the  soil  is 
ridged,  and  during  the  preparation  of  the  ridge  the 
fertilizer  may  be  distributed  in  it  and  well  mixed  with 
the  soil.  Where  the  land  contains  more  clay  and 
humus  it  is  frequently  advocated  that  the  potash 
manures  be  applied  broadcast  the  previous  year,  and 
only  the  nitrogenous  fertilizer  and  superphosphate  be 
applied  immediately  to  the  plant.  On  soils  of  this 
latter  character,  this  is  doubtless  the  best  system.  If 
kainit, — which  has  been  found  to  be  preferable  to  mu- 
riate in  the  Georgia  experiments  referred  to, — is  used 
as  the  source  of  potash,  it  is  very  necessary  that  it  be 
well  mixed  with  the  soil  before  setting  out  the  plants. 
Heavy  applications  of  this  salt  in  the  spring  proved 
injurious   in   the    experiments  conducted  at  the  New 


226  FERTILIZERS 

Jersey  Station.*  The  effect  of  fertilizers  upon  the 
chemical  composition  of  the  tuber  was  chiefly  to  reduce 
dry  matter,  and  not  apparently  to  affect  edible  quality, 
though  the  experiments  were  carried  out  upon  the 
general  crop  rather  than  upon  those  grown  for  high 
quality. 

TOMATOES 

Tomatoes  are  largely  grown  as  a  field  crop,  and 
the  object  of  their  growth,  whether  for  the  early 
market  or  for  the  canneries,  is  a  factor  that  must  be 
considered  in  the  adoption  of  systems  of  fertilization. 

Field  Experiments   with   Fertilizers  for  Tomatoes 

The  impression  is  very  prevalent  among  growers 
that  the  tomato  does  not  require  heavy  manuring. 
Studies  made  at  a  number  of  experiment  stations! 
show,  however,  that  the  tomato  is  a  plant  that  quickly 
and  profitably  responds  to  the  use  of  manures  or  ferti- 
lizers, and  that  the  maturity  and  yield  are  very  largely 
influenced  by  the  method  of  manuring  and  fertilizing. 
Experiments  were  conducted  by  the  New  Jersey  Station 
upon  three  farms  located  in  different  parts  of  the  state, 
and  during  four  seasons,  the  object  of  which  was  to 
test  the  effect  on  maturity  and  yield  of  the  early  crop 


*  Bulletin  P,  New  Jersey  Experiment  Station. 

t Bulletins  Nos.  21  and  32,  Cornell  Experiment  Station  (Ithaca).  Bulletin 
No.  17,  Georgia  Exi)eriment  Station.  Annual  Report  for  1891,  Maryland  Experi- 
ment Station.  Bulletin  No.  11,  Virginia  Experiment  Station.  Bulletins  Nos.  63, 
79  and  O,  and  Report  for  1892,  New  Jersey  Experiment  Station. 


THE  NEW  JERSEY  EXPERIMENTS  227 

of  the  use  of  nitrate  of  soda  in  different  quantities 
and  at  different  times,  both  with  and  without  the  ad- 
dition of  the  mineral  elements,  phosphoric  acid  and 
potash,  and  to  make  a  comparison  of  these  with  barn- 
yard manure.     The  results  showed  : 

First.  That  nitrate  of  soda  was  one  of  the  best 
nitrogenous  fertilizers  for  this  crop,  and  that  its  use 
in  small  quantities  (160  pounds  per  acre),  or  in  large 
quantities  (320  pounds  per  acre)  in  two  applications, 
increased  the  yield  materially,  but  not  at  the  expense 
of  maturity,  and  that  this  was  equally  true  when  used 
alone  and  when  used  in  connection  with  phosphoric 
acid  and  potash. 

Second.  That  nitrate  of  soda,  when  used  in  large 
quantities  (320  pounds  per  acre)  in  one  application,  in 
the  presence  of  a  sufficient  excess  of  phosphoric  acid 
and  potash,  did  increase  the  yield,  but  at  the  expense 
of  maturity. 

Third.  That  when  properly  used,  nitrate  of  soda 
was  a  profitable  fertilizer  for  the  crop. 

It  was  shown,  furthermore,  that  nitrate  of  soda  was 
superior  to  both  barnyard  manure  and  mineral  ferti- 
lizers alone,  and  on  the  whole,  was  but  slightly  less 
effective  than  the  complete  fertilizers. 

Fertilizers  for   the   Early    Crop  for  Different 
Conditions   of  Soil 

These  results  have  been  practically  confirmed  both 
by  the  experiments  of  the  stations  referred  to,  and 
also  in  actual   practice  on  soils  similar  in  character ; 


228  FERTILIZERS 

namely,  those  which  were  well  adapted  for  the  early 
tomato  —  light,  well -drained  sandy  loams  —  and  which 
had  been  previously  well  manured  for  crops  entering 
the  rotation.  The  results  do  not  apply  in  the  case  of 
very  poor  soils,  or  upon  heavy  clay  soils,  which  are 
not  adapted  for  the  early  crop. 

The  statement  that  it  pays  to  fertilize  early  toma- 
toes, and  that  nitrate  of  soda  is  one  of  the  best  ferti- 
lizers for  the  crop,  must,  therefore,  be  accompanied  by 
statements  regarding  the  condition  of  soil  and  the 
purpose  of  growth.  With  the  conditions  clearly  under- 
stood, a  scheme  of  fertilization  for  early  tomatoes  may 
be  outlined  which,  when  the  conditions  are  observed, 
will  be  likely  to  give  much  better  results  than  methods 
of  fertilization  which  do  not  take  into  consideration 
the  habits  of  the  plant  and  the  special  object  of  its 
growth. 

For  example,  on  soils  which  have  been  well  sup- 
plied with  the  mineral  elements,  phosphoric  acid  and 
potash,  by  previous  manuring  or  fertilizing,  a  ferti- 
lizer very  rich  in  nitrogen  derived  from  nitrate  of 
soda,  or  nitrate  of  soda  alone,  should  be  used ;  the 
application  at  the  time  of  setting  the  plant  to  be 
equivalent  in  nitrogen  to  from  80  to  100  pounds  of 
nitrate  of  soda,  with  a  second  application  of  an  equiv- 
alent amount  made  from  three  to  four  weeks  later. 
A  single  application  of  the  amount  here  suggested  at 
the  time  of  setting  the  plants  would,  perhaps,  under 
good  seasonal  conditions  give  results  quite  as  good, 
though  the  heavier  application  of  nitrate  at  one  time 
may  result,  in  certain  cases,  in  the  loss  of  nitrogen 


FERTILIZATION  OF  TEE  EARLY  CROP         229 

by  leaching,  since  it  is  an  extremely  soluble  salt.  In 
this  case  a  deficiency  of  food  would  result,  and  thus 
prevent  the  normal  development  of  both  plant  and 
fruit. 

On  soils  which  possess  only  good  mechanical  con- 
dition, and  are  very  poor  in  plant -food,  a  heavier 
application  of  both  nitrogen  and  the  mineral  elements 
will  be  required,  in  which  case  the  following  fertiliza- 
tion is  recommended  : 

Previous  to  setting  the  plants,  or  at  the  time  they 
are  set,  apply  50  pounds  per  acre  of  phosphoric  acid, 
preferably  derived  from  superphosphate,  and  100 
pounds  of  potash,  derived  from  muriate,  and  thor- 
oughly harrow  or  cultivate  into  the  soil ;  and  at 
the  time  of  setting  apply  around  the  hill  100  to  150 
pounds  per  acre  of  nitrate  of  soda.  Three  to  four 
weeks  later,  make  another  application  of  from  100  to 
150  pounds  per  acre  of  nitrate  of  soda.  Owing  to  the 
small  bulk  of  nitrate,  it  should  be  mixed  with  dry 
soil  or  sawdust,  in  order  to  insure  even  distribution. 
The  only  precaution  to  be  observed  is  to  prevent  its 
immediate  contact  with  the  plant  roots.  If  these 
methods  are  practiced,  the  plant  secures  its  nitrogen 
in  an  immediately  available  form  at  a  time  when  it 
is  needed, — when  it  is  set  in  the  field.  There  is 
thus  no  delay  in  growth,  and  because  of  the  presence 
of  an  abundance  of  the  mineral  elements  no  ex- 
cessive growth  of  vine  is  encouraged  by  the  use  of 
the  nitrate,  as  would  be  the  case  were  the  mineral 
elements  absent.  Inasmuch  as  the  nitrogen  is  ap- 
plied  close   to   the   plants  it   is  within   the  immediate 


230  FERTILIZERS 

reach  of  its  roots ;  and  because  it  is  all  in  an  im- 
mediately available  form,  which  is  used  up  rapidly, 
the  tendency  to  late  plant  growth,  which  would  be 
caused  by  a  continuous  supply  of  nitrogen,  is  not  en- 
couraged, and  a  normal  and  rapid  growth  and  de- 
velopment of  fruit  results. 

It  is  not  stated  that  by  this  method  of  fertilization 
maturity  is  increased  in  the  sense  that  the  date  of  the 
first  picking  is  earlier,  but  that  a  larger  number  of 
fruits  is  picked  earlier.  It  was  not  shown  in  any  of 
the  experiments  that  the  date  of  picking  was  made 
earlier  by  virtue  of  the  nitrate,  for,  in  fact,  the 
earliest  tomatoes  were  picked  upon  land  where  the 
minerals  only  had  been  applied.  Here  the  yield  was 
not  satisfactory,  but  where  the  nitracte  was  applied, 
because  of  the  larger  crop,  a  larger  proportion  of 
early  tomatoes  was  secured.  It  is  obvious  that,  in- 
asmuch as  the  price  of  the  fruit  rapidly  declines  as 
the  season  advances,  receipts  from  the  proportionately 
larger  quantity  of  early  fruit  will  be  materially 
increased. 

The  Use  of  Fertilizers  with  Yard  Manures 

When  it  is  desirable  to  use  yard  manures  with  fer- 
tilizers for  tomatoes,  because  of  the  abundance  and 
cheapness  of  the  former,  they  should  be  applied  broad- 
cast; and  the  nitrate  applied  at  the  time  of  planting,  as 
already  described,  rather  than  both  together  in  the  hill. 
The  tendency  in  the  latter  case  will  be  to  cause  a  loss 
of    nitrogen   from    the    nitrate,    depending    upon    the 


FERTILIZATION  OF   THE  LATE  CROP  231 

amount  of  organic  matter  in  the  manures.  That  is, 
experiments  and  experience  have  shown  that  under 
these  circumstances  more  or  less  of  the  nitrogen  in  the 
nitrate  may  be  lost. 

In  the  use  of  yard  manures  for  early  tomatoes,  the 
application  of  excessive  quantities  should  be  avoided, 
as  they  are  virtually  nitrogenous  manures,  which, 
because  of  their  organic  character,  feed  the  plant  in 
proportion  to  their  rate  of  decay.  Hence,  the  presence 
of  large  quantities  will  encourage  not  only  an  undue 
growth  of  plant,  but  a  late  growth  as  well.  The 
mineral  fertilizers,  as  acid  phosphate  and  muriate  of 
potash,  can  be  used  with  the  yard  manures  with  perfect 
safety,  in  fact,  with  great  advantage,  because  supple- 
menting their  proportionate  lack  of  the  mineral  con- 
stituents. It  is  also  desirable,  where  it  is  the  practice 
to  use  manure,  particularly  if  it  is  coarse,  to  spread  it 
during  the  winter,  in  order  that  the  soluble  portions 
may  become  thoroughly  distributed  throughout  the 
soil.  As  soon  as  the  land  is  ready  to  work  in  the 
spring,  it  should  again  be  plowed  shallow  and  then 
deeply  tilled,  in  order  both  to  thoroughly  warm  up  the 
soil,  and  to  incorporate  with  it  coarser  portions  of  the 
manure. 

Fertilizers  for  Late  Tomatoes 

In  manuring  and  fertilizing  for  the  late  crop,  the 
character  of  the  crop  and  the  season  of  its  growth 
should  be  remembered.  In  the  first  place,  the  plants 
for  this  crop  are  not  put  in  the  soil  until  summer,  when 
the  conditions  are  most  favorable  for  the  rapid  change 


232  FEBTILIZERS 

of  organic  forms  of  nitrogen  into  nitrates.  Thus,  if 
the  soil  has  been  manured  or  is  naturally  rich  in  vege- 
table matter,  the  additional  application  of  nitrogen  in 
immediately  available  forms  is  not  so  important.  In 
the  second  place,  the  object  of  the  growth  is  not  early 
maturity,  but  the  largest  yield  of  matured  fruit ;  hence 
it  is  more  desirable  to  grow  a  larger  plant  than  in  the 
case  of  the  early  tomatoes.  The  fertilization  should, 
therefore,  be  such  as  to  furnish  an  abundance  of  all  the 
elements  of  plant -food;  and,  inasmuch  as  the  tomato 
belongs  to  the  potash -consuming  class  of  plants,  any 
fertilization  should  be  particularly  rich  in  this  element. 
It  is  not  to  be  understood,  however,  that  it  is  not 
necessary  to  apply  nitrogen,  for  frequently  soils  are 
used  that  are  either  not  well  adapted  for  the  plant  or 
are  poor,  not  having  been  previously  well  supplied  with 
vegetable  matter  containing  nitrogen.  On  such  soils, 
additional  applications  are  very  important,  and  nitrate 
of  soda  is  one  of  the  best  forms  to  use,  as  it  is  absorbed 
freely  by  the  roots,  encouraging  an  early  and  vigor- 
ous growth  of  plant  and  a  normal  development  of 
fruit.  Slow-acting  organic  forms  of  nitrogen,  on  the 
other  hand,  frequently  begin  to  feed  the  plant  and 
cause  its  rapid  growth  when  the  energies  should  be 
concentrated  in  the  growth  and  maturity  of  fruit. 
Fertilizers  that  have  proved  very  excellent  are  those 
which  contain  a  relatively  smaller  amount  of  nitrogen 
than  is  required  for  early  tomatoes,  and  are  richer  in 
phosphoric  acid  and  potash. 

A  study  of  the  composition  of   both  the  fruit  and 
vine   of    the   tomato   will    serve   to   guide   us    in   this 


COMPOSITION  OF  FRUIT  AND    VINE  233 

respect,  though  the  amounts  and  proportions  of  food 
removed  by  any  crop  are  not  absolute  guides,  inas- 
much as  the  soil  may  furnish  more  of  one  constituent 
than  another,  and  because  the  plant  may  have  the 
power  of  acquiring  certain  of  its  constituents  more 
readily  than  others.  The  analyses  of  the  fruit  and 
vines  of   tomatoes  show  that  one  ton  contains  : 

Nitrogen      Phosphoric  Acid      Potash 
lbs.  lbs.  lbs. 

In  fruit 3.20  1.00  5.40 

Vines  (green)  .    .    .  6.40  1.40  10.00 

Ten  tons  of  the  fruit,  with  the  accompanying 
vines,  which  would  probably  reach  four  tons,  would 
contain  57  pouiyis  of  nitrogen,  16  of  phosphoric  acid 
and  94  of  potash.  On  a  good  soil,  therefore,  which 
without  manure  would  produce  five  or  six  tons, 
there  should  be  added  a  sufficient  excess  of  the 
constituents  to  provide  for  a  maximum  production, 
and  the  materials  should  be  relatively  richer  in  nitro- 
gen and  potash  than  in  phosphoric  acid.  A  mixed 
fertilizer   composed   of : 

Nitrate  of  soda 400  lbs. 

Bone  tankage 700     " 

Acid  phosphate 400     " 

Muriate  of  potash 500     *' 

would  contain,  approximately,  95  pounds  of  nitrogen, 
144  of  phosphoric  acid  and  250  of  potash  in  each  ton. 
An  application  of  500  pounds  per  acre  of  this  mixture 
would  furnish  half  as  much  nitrogen  as  is  contained 
in  a  crop  of  ten  tons,  nearly  as  much  immediately 
available    phosphoric   acid,    and    two -thirds    as    much 


234  FEBTILIZEB8 

potash.  Hence  a  dressing  containing  the  amounts, 
kinds  and  proportions  of  plant -food  here  shown  would 
be  regarded  as  very  desirable,  since  one -half  of 
the  nitrogen  is  in  the  form  of  a  nitrate,  which  would 
contribute  to  the  immediate  growth  of  the  plant.  The 
amount  of  soluble  and  available  phosphoric  acid  is 
sufficient  to  satisfy  the  needs  of  the  crop  throughout 
its  entire  growth,  and  such  an  abundance  of  potash 
as  to  contribute  to  the  normal  development  of  both 
plant  and  fruit.  Formulas  of  this  character  have 
been  used  with  good  results,  though  the  large  pro- 
portion of  salts  sometimes  make  mixtures  of  this  sort 
too  moist  to  handle  well,  in  which  case  a  part  of  the 
potash,  or  even  of  the  nitrate,  may  be  applied 
separately  with  advantage.  On  poorer  soils,  the  arti- 
ficial supply  of  plant -food  should  be  proportionately 
greater,  or  sufficient  to  provide  for  the  entire  needs 
of  a  fair -sized  crop,  since  as  a  rule  the  relative  power 
of  the  plant  to  acquire  food  is  somewhat  slighter  on 
poor  soils  than  on  good  soils;  or,  stated  in  another 
way,  the  results  from  the  use  of  fertilizers  are  pro- 
portionately better  upon  soils  in  good  condition  than 
upon  those  not  well  cared  for.  A  good  formula  for 
these  may  consist  of : 

Nitrate  of  soda 500  lbs. 

Bone  tankage 500    " 

Acid  phosphate 400    " 

Muriate  of  potash 600    " 

One  ton  of  this  mixture  would  furnish,  approximately, 
105  pounds  of  nitrogen,  120  of  phosphoric  acid  and 
300   of    potash.      The   application   of    1,000    pounds, 


NEJiD  FOR  NITBOOfJN  REDUCED  235 

therefore,  would  furnish  the  food  in  sufficient  abun- 
dance and  in  good  proportions  to  meet  the  demands 
of  a  fair  crop. 

The  advantage  of  using  so  large  a  proportion  of 
nitrogen  in  the  form  of  nitrate  of  soda  in  this  case 
is,  that  it  is  immediately  available,  inducing  the  im- 
mediate and  rapid  growth  of  plant,  and  preventing  a 
too  late  growth  by  furnishing  a  minimum  of  organic 
nitrogen,  which  would  become  available  late  in  the 
season.  The  cost  of  the  fertilizer  suggested  in  these 
cases  is  high,  and  the  necessity  of  so  expensive  a 
dressing  could  be  materially  reduced  by  decreasing 
the  need  for  nitrogen,  particularly  in  organic  forms, 
which  may  be  accomplished  by  sowing  crimson  clo- 
ver with  or  after  the  previous  crop  of,  say,  corn  or 
tomatoes.  If  weather  conditions  are  favorable,  crim- 
son clover  maj^  be  sown  in  the  tomato  fields  in 
August,  after  cultivation  has  ceased,  or  at  the  last 
cultivation,  and  a  crop  of  clover  grown  which  will 
provide  nitrogen  for  the  next  year's  crop.  This 
method  is  now  practiced  with  advantage  by  many 
growers.  The  late  crop,  like  potatoes  and  sweet  pota- 
toes, is  usually  grown  in  rotations  in  which  it  is  the 
chief  money  crop;  hence  the  unused  residue  from  fer- 
tilizers applied  in  large  amounts,  as  here  indicated, 
contributes  largely  to  the  economical  growth  of  sub- 
sequent  crops. 

SUGAR  BEETS 

The  purpose  in  the  growth  of  sugar  beets  is  to 
obtain  the  largest  total   yield  of  sugar  per  acre;   and 


236  FERTILIZERS 

inasmuch  as  the  sugar  content  of  the  beet,  as  well  as 
its  right  growth  and  development,  is  very  largely 
influenced  by  the  character  of  the  fertilization,  this 
matter  becomes  of  very  considerable  importance,  in 
view  of  the  promising  development  of  the  sugar  beet 
industry  in  this  country.  Thus  far,  information  con- 
cerning the  use  of  fertilizers  is  derived  largely  from  the 
results  obtained  in  other  countries,  where  it  has  been 
a  prominent  crop,  and  where  great  attention  has  been 
paid  to  this  factor  in  its  production. 

Tlie  Demands  of  the  Crop  for  Plant- food 

The  sugar  beet  draws  heavily  upon  the  soil  for  the 
nitrogen  and  potash  constituents.  A  minimum  yield  of 
10  tons  of  topped  beets  contains  44  pounds  of  nitrogen, 
20  of  phosphoric  acid  and  96  of  potash.  On  medium 
loamy  soils,  which  by  their  character  are  well  adapted 
for  the  growth  of  the  sugar  beet,  heavy  fertilization 
with  potash,  however,  has  not  been  found  to  be  de- 
sirable; while  on  light  soils,  which  are  also  well  adapted 
for  the  crop,  liberal  manuring  with  potash  becomes 
absolutely  necessary. 

As  in  this  crop,  the  object  of  the  growth  is  to  se- 
cure not  primarily  beets,  but  sugar,  and  since  the  sugar 
formation  is  not  perfected  until  the  absorption  of  the 
necessary  food  from  the  soil  has  been  in  large  part 
completed,  any  fertilization  which  promotes  a  too  rapid 
or  too  long  continued  growth  has  a  tendency  to  reduce 
the  percentage  of  sugar;  and  inasmuch  as  the  matu- 
ration takes  place  largely  in  the  moi^ths  of  early  fall, 


FERTILIZATION  OF  SUGAR  BEETS  237 

the  growth  must  be  forced  early  in  the  season.  That 
is,  it  is  essential  that  a  large  and  rapid  leaf  growth  be 
made  early,  in  order  that  the  food  from  the  air  may  be 
acquired.  It  has  been  demonstrated  that  for  this  early 
and  rapid  growth  of  the  beet,  phosphoric  acid  is  one 
of  the  most  essential  constituents,  which  explains  the 
need  for  phosphoric  acid  in  larger  proportion  than  is 
indicated  by  the  composition  of  the  beet.  The  crop 
requires  a  considerably  greater  supply  of  phosphoric 
acid  at  this  stage  of  its  growth  than  other  farm  crops 
which  are  quite  as  exhaustive,  and  it  is  also  evident 
that  in  order  that  the  crop  may  obtain  the  phosphoric 
acid  at  this  period,  it  must  be  soluble  and  immediately 
available ;  hence  the  larger  portion  of  this  element 
applied  should  be  derived  from  superphosphates.  In 
the  matter  of  fertilization  with  nitrogen,  the  object  of 
the  growth  must  also  be  kept  in  view.  An  application 
which  would  encourage  steady  and  continuous  growth, 
rather  than  an  early  and  rapid  growth,  while  contrib- 
uting to  a  large  yield,  causes  a  reduction  in  the  sugar 
content  of  the  beet.  Hence  it  is  strongly  urged  by 
those  who  are  in  a  position  to  give  sound  advice,  that 
the  early  nitrogen  fertilization  should  consist  of  the 
quickly  available  forms,  nitrate  or  ammonia,  and  that 
the  organic  or  slower -acting  forms  should  not  be 
applied  in  such  excess  as  to  encourage  a  late  growth. 
Hence  it  is,  that  upon  medium  and  light  lands  the  use 
of  commercial  fertilizers  has  proved  of  greater  service 
in  the  growing  of  this  crop  than  the  exclusive  use  of 
yard  manure,  and  in  such  quantities  as  to  supply  the 
entire  needs  of  the  plant.     In  the  use  of  fertilizer,  not 


238  FERTILIZERS 

only  the  total  supply  of  the  constituents,  but  their 
form,  may  be  regulated  to  the  needs  under  different 
conditions,  thus  permitting  a  full  feeding  of  the  plant, 
and  at  a  time  most  suitable  to  accomplish  the  object 
in  view, —  advantages  which  are  not  possessed  by  the 
natural   manures. 

A  fertilization  which  would  meet  the  needs  both  in 
respect  to  quantity  and  kind  of  fertilizers,  may  be  as 
follows : 

On  good  soils,  the  application  or  a  fertilizer  con- 
taining from  40  to  50  pounds  of  nitrogen,  from  50  to 
60  of  phosphoric  acid  and  from  40  to  50  of  potash, 
would  be  sufficient  to  meet  the  demands  of  the  plant. 
The  nitrogen  supplied  should  be  derived  largelj"^  from 
nitrates  or  ammonia,  or  both,  and  the  phosphoric  acid 
from  a  superphosphate,  while  the  potash  may  be  de- 
rived from  sulfate  or  muriate  of  potash.  The  former 
is  preferable  if  applied  during  the  spring  preceding 
the  planting  of  the  beets.  While  it  is  frequently 
desirable,  for  convenience  and  economy  of  labor  in 
applying,  that  the  fertilizer  should  be  mixed,  in  order 
to  prevent  any  waste  of  soluble  nitrogen,  it  should  be 
applied  in  fractional  dressings.  For  example,  a  mix- 
ture of  250  to  300  pounds  of  nitrate  of  soda  (or,  the 
nitrogen  may  be  derived  partly  from  nitrate  and  partly 
from  ammonia),  400  to  500  pounds  superphosphate, 
and  80  to  100  of  muriate  or  high-grade  sulfate  of 
potash,  should  be  applied  in  two  or  three  dressings. 
A  part  only  should  be  applied  previous  to  sowing,  for 
both  the  nitrate  and  the  potash  salts  have  a  depress- 
ing effect  upon  germination.     They  are  preferably  ap- 


ADVANTAGES   OF  DEEP  CULTIVATION  239 

plied,  say,  one -third  of  the  mixture  as  soon  as  the 
plants  have  come  up,  another  third  immediately  after 
or  before  the  first  cultivation,  and  the  remainder 
immediately  after  or  before  the  second  cultivation. 
The  application  of  the  fertilizers  in  these  forms  and 
at  the  times  indicated  insures  the  rapid  and  early 
growth  and  development  of  the  plant ;  and  by  reason 
of  the  solizbility  of  the  nitrates  and  ammonia  salts,  a 
late  feeding  of   the  plant  with  nitrogen  is  obviated. 

On  light  or  medium  soils,  the  amount  of  plant- 
food  should  be  increased  by  at  least  one -third,  though 
fractional  applications  should  be  made  as  previously 
recommended.  On  soils  rich  in  vegetable  matter,  a 
part  of  the  nitrogen  may  be  omitted,  though  the  phos- 
phoric acid  should  not  be  reduced. 

The  Influence  of  Previous  Beep   Cultivation  of  Soil 

Another  point  to  observe  in  the  growing  of  beets 
for  sugar, — and  it  also  has  an  immediate  bearing  upon 
fertilization, —  is  the  character  of  the  previous  cultiva- 
tion. If  the  soils  have  not  been  deeply  and  well  culti- 
vated, so  large  a  dressing  as  is  here  recommended 
would  be  likely  to  be  deleterious,  as  with  a  shallow 
and  poorly  prepared  soil  plants  would  have  less  op- 
portunity to  penetrate  deeply,  and  thus  too  great  a 
growth  above  the  surface  of  the  ground  would  be 
encouraged,  with  a  consequent  lowering  of  sugar  eon- 
tent  as  well  as  yield. 

The  best  practice  in  our  country  will  have  to  be 
developed    by   the    experience    of    our    own    growers, 


240  FERTILIZERS 

though  in  the  absence  of  such  experience,  the  recom- 
mendations here  made  may  be  relied  upon.  In  many 
of  the  sections  of  this  country  in  which  the  soils  and 
climate  are  well  adapted  for  the  sugar  beet  industry, 
the  needs  as  yet  are  quite  as  much  for  improv^ed 
methods  of  cultivation  as  for  added  fertility.  They 
have  not  been  exhausted  of  their  essential  elements 
of  fertility. 

An  epitome  of  the  soil  conditions  for  sugar  beet 
culture  will  be  found  in  the  second  edition  of 
Roberts'  "Fertility  of    the   Land,"  p.   405. 


CHAPTER  XII 

GREEN  FORAGE    CROPS 

A  LARGE  number  of  crops  is  included  in  this  class. 
In  dairy  districts  they  are  grown  for  summer  feeding, 
mainly  to  supplement  or  to  entirely  substitute  pas- 
turage, as  well  as  to  provide  a  succulent  ration  of 
roughage  in  winter.  Any  crop  which  grows  quickly, 
is  palatable,  and  makes  a  reasonably  large  yield,  is 
adapted  for  the  purpose.  For  convenience  of  study, 
these  crops  may  be  further  classified  into  three 
groups  : 

1.  Cereals  and  grasses.  2.  Clovers  and  other 
legumes.     3.  Roots  and  tubers. 

In  the  case  of  those  included  in  the  first  group,  the 
purpose  or  object  is  to  obtain  as  large  a  growth  of 
leaf  and  stem  as  possible.  Thus  the  character  of  the 
fertilization  may  differ  from  that  recommended  when 
the  same  crops  are  grown  for  the  primary  purpose  of 
obtaining  the  largest  yield  of  seed  or  grain.  These 
crops,  too,  may  in  all  cases  be  considered  as  only  well 
adapted  for  the  "intensive"  system  of  practice — that 
is,  when  the  management  is  such  as  to  encourage  the 
largest  yield  possible  per  unit  of  area  under  the  ex- 
isting conditions  of  climate  and  season.  The  natural 
fertility  of  the  soil  thus  becomes  a  less  important 
factor ;  indeed  it  cannot  be  relied  upon  altogether,  as 
p  (241) 


242  FJEBTILIZEBS 

the  largest  yield  of  succulent  food  is  dependent  upon 
a  rapid  and  continuous  growth,  and  hence  the  supply 
of  plant -food  must  be  relatively  much  greater  than  is 
the  case  when  the  cereals  are  grown  for  their  seed. 
That  is,  forage  crops,  because  succulence  is  a  factor 
influencing  quality,  must,  as  a  rule,  be  grown  quickly, 
and  in  order  that  large  yields  may  be  obtained  in  a 
short  period  of  time  a  relatively  greater  abundance  of 
plant -food  must  be  at  their  disposal  than  when  the 
growth  is  distributed  through  a  longer  period.  Be- 
sides, larger  amounts  of  all  of  the  food  constituents 
are  required  for  the  production  of  the  same  amount  of 
dry  matter  per  acre  than  when  grown  for  the  mature 
crop,  because  the  dry  matter  of  the  mature  crop  is 
richer  in  the  constituents  derived  from  the  air  and 
poorer  in  those  derived  from  the  soil,  than  the  dry 
matter  of  the  immature  crop. 

Maize  {Com)  Forage 

A  valuable  forage  crop  of  the  first  group  is  maize 
(Indian  corn),  because  it  grows  quickly,  is  well  adapted 
for  a  wide  variety  of  soils  and  climates,  is  extremely 
palatable,  and  is  capable  of  producing  large  yields. 
The  fertilization  which  has  been  recommended  for  the 
field  crop  is  less  desirable  than  one  which  furnishes  a 
greater  proportion  of  nitrogen,  because  of  the  greater 
need  of  this  element,  and  because  it  encourages  a 
larger  leaf  and  stalk  growth;  and  the  greater  the  pro- 
portion of  these  in  a  corn  crop  the  richer  will  be  the 
dry  matter   in   the   important   compound   protein,  and 


FERTILIZERS   FOR    CORN  FORAGE  243 

nitrogen  is  the  basic  element  in  this  group  of  nu- 
trients. 

When  the  crop  is  grown  on  good  land  on  clover 
sod,  which  has  been  liberally  manured,  the  fertilizers 
applied  should  be  particularly  rich  in  the  mineral 
elements,  phosphoric  acid  and  potash.  An  application 
of  500  pounds  of  a  mixture  containing — 

Nitrogen 2% 

Available  phosphoric  acid Q% 

Potash B% 

would  provide  an  abundance  of  food,  even  should 
unfavorable  conditions  intervene,  but  when  grown  on 
light,  unmauured  soil  without  sod,  a  larger  amount  of 
nitrogen  should  be  used  in  connection  with  the  min- 
erals. An  application  of  25  pounds  of  nitrogen,  35  of 
phosphoric  acid  and  50  of  potash  is  as  small  a  fer- 
tilization as  should  be  recommended  on  soils  of  this 
character,  since  a  yield  of  10  tons  per  acre,  containing 
25  per  cent  of  dry  matter  —  which  is  only  a  fair  crop 
— would  remove  60  pounds  of  nitrogen,  25  of  phosphoric 
acid  and  70  of  potash.  Hence,  very  large  increases  in 
yield  could  not  be  expected  from  smaller  dressings, 
unless  conditions  were  absolutely  favorable  throughout 
the  entire  period  of  growth.  The  nitrogen,  as  in  the 
case  of  field  corn,  may  be  derived  from  organic  sources, 
as  the  season  of  growth  is  the  same — the  summer — which 
is  the  most  favorable  for  encouraging  a  rapid  change 
of  the  organic  nitrogen  into  the  soluble  nitrates.  The 
phosphoric  acid  should  be  in  large  part  derived  from 
superphosphates,   though   since   the  season  of    growth 


244  FEETILIZEBS 

and  the  character  of  the  crop  and  of  its  cultivation  are 
conditions  all  of  which  favor  a  rapid  change  of  in- 
soluble into  available  forms,  a  portion  may  be  sup- 
plied by  ground  bone  or  tankage.  The  potash  may  be 
kainit  or  muriate,  though  if  kainit  is  used,  it  should 
be  broadcasted  and  well  worked  into  the  soil  before 
planting. 

Silage  Corn 

Corn  grown  for  the  silo,  while  distinctly  a  forage 
crop,  is,  in  its  management,  very  similar  to  the  field 
crop,  and  is  not  planted  so  thickly  as  to  prevent  the 
formation  of  ears.  The  object  in  its  growth  is,  how- 
ever, to  obtain  a  large  yield  of  dry  matter,  somewhat 
richer  in  nitrogenous  substance  and  poorer  in  starch 
and  woody  fiber  than  field  corn.  Hence  the  fertilizers 
for  the  crop  on  medium  soils  should  be  richer  in 
nitrogen  than  for  the  field  corn,  where  the  primary 
object  is  the  grain,  and  where  heavy  fertilization  with 
nitrogen  would  encourage  a  disproportionate  stalk 
growth.  An  application  of  30  pounds  of  nitrogen 
(equivalent  to  250  pounds  of  dried  blood  or  450  of  cot- 
ton-seed meal),  40  of  phosphoric  acid  (equivalent  to 
300  pounds  of  acid  phosphate),  and  60  of  potash 
(equivalent  to  120  pounds  of  muriate  of  potash), 
would  provide  for  a  marked  increase  in  yield. 

Wheat  and  Eye  Forage 

In  the  growth  of  cereal  grains,  the  object  is  to 
secure  as  large  a  yield   of  grain  as   is  possible  under 


WHEAT  AND  BYE  FORAGE  245- 

the  conditions  of  climate  and  season,  and  only  such 
development  of  leaf  and  stem  as  will  contribute  to  a 
maximum  yield  of  grain.  Hence  a  too  liberal  nitrog- 
enous fertilization  which  encourages  this  form  of 
growth  may  result  in  too  great  a  proportionate  yield  of 
straw.  This  objection  becomes  an  advantage  when  the 
cereals  -are  grown  for  forage. 

The  cereal  crops,  wheat  and  rye,  if  seeded  in  the 
fall,  should,  therefore,  receive  a  fertilizer  which  shall 
especially  promote  leaf  and  stem  growth  ;  and  to  ac- 
complish this  purpose  in  the  best  manner,  a  rapid  early 
fall  growth,  and  a  consequent  deep  rooting  system,  as 
well  as  an  early  and  rapid  spring  growth,  should  be 
encouraged.  Fertilizers  most  suitable  are  rich  in 
nitrogen  and  phosphoric  acid,  and  should  contain 
potash  also,  if  the  land  has  not  been  previously  well 
supplied  with  this  element.  The  larger  proportion  of 
the  nitrogen,  however,  should  be  applied  in  available 
forms  as  a  top-dressing  in  the  spring,  rather  than  at 
time  of  seeding,  thus  reducing  the  possible  loss  of  this 
element  during  the  winter  and  early  spring  through 
leaching,  besides  providing  the  plant  with  it  when 
most  needed,  and  producing  a  crop  richer  in  nitrog- 
enous substance. 

The  ranker  growth  and  somewhat  coarser  product 
resulting  from  this  method  of  fertilization,  while  not 
desirable  for  grain  crops,  is  not  a  detriment  when  the 
product  is  cut  in  its  green  stage  for  feeding,  and  the 
larger  growth  is  accompanied  by  greater  succulence. 

Where  these  cereal  grains  are  sown  mainly  as 
catch  crops   following    a   corn    crop   which    has   been 


246  FEET  I L IZERS 

liberally  fertilized  with  the  minerals  phosphoric  acid 
and  potash,  the  application  at  time  of  seeding  may  be 
light,  and  may  consist  only  of  nitrogen  and  phosphoric 
acid, — for  example,  from  200  to  400  pounds  per  acre  of 
a  dissolved  bone  ;  and  the  top-dressing  in  the  spring 
need  not  exceed  100  pounds  of  nitrate  of  soda  per  acre 
for  the  wheat,  and  75  pounds  per  acre  for  the  rye. 
For  lighter  soils,  or  for  those  not  previously  well  fer- 
tilized, much  heavier  applications  not  only  are  required, 
but  all  of  the  constituents  should  be  included,  and 
the  top-di'essings  should  be  made  in  spring,  as  ah-eady 
pointed  out. 

Spring  Bye 

For  spring  rye,  an  application  of  a  fertilizer  fur- 
nishing 10  pounds  of  nitrogen,  20  of  phosphoric  acid 
and  10  of  potash  per  acre  would  be  a  sufficiently 
liberal  dressing  for  the  crop  on  good  soils,  since  the 
plant  possesses  good  foraging  powers,  though  it  is  not 
so  desirable  a  forage  crop  for  northern  climates  as  the 
winter  rye.  The  nitrogen,  in  any  case,  should  be  in 
quickly  available  forms. 

Oats 

Oats  and  millet  are  also  suitable  crops  for  forage 
purposes,  and  are  largely  grown  ;  the  first,  because  it 
is  adapted  for  cool,  moist  weather,  and  makes  a  rapid 
early  growth,  and  the  second,  because  adapted  for  late 
spring  seeding  and  for  summer  conditions. 

The   oat   crop   for   forage    purposes    is   even   more 


A    PJL'CULIARITr    OF    THE    OAT    CROP  247 

generally  benefited  by  manuring  than  when  grown  for 
the  grain,  and  the  constituents  particularly  useful  are 
nitrogen  and  phosphoric  acid,  though  on  sandy  soils, 
and  on  those  of  medium  fertility  and  not  previously 
fertilized  with  potash,  this  element  should  also  be 
added. 

A  good  dressing,  keeping  in  mind  the  value  of  the 
possible  increased  yield,  may  consist  of  12  pounds  of 
nitrogen,  20  of  phosphoric  acid  and  10  of  potash, —  the 
nitrogen  largely  in  the  form  of  a  nitrate  and  the  phos- 
phoric acid  in  soluble  and  available  forms. 

The  oat  crop  is  peculiar  in  that  shortly  after  the 
germination  of  the  seed,  there  usually  occurs  a  period 
of  a  week  or  ten  days  during  which  the  growth  is  ex- 
tremely slow,  which  experienced  farmers  call  the  "pout- 
ing" period.  While  the  exact  cause  of  this  well-known 
habit  is  not  understood,  it  is  believed  to  be  due 
in  part  to  the  absence  of  available  plant -food  of  the 
right  sort  early  in  the  season,  since  liberal  applications 
of  nitrates  and  superphosphates  seem  to  shorten  the 
period  of  "pouting,"  if  not  altogether  preventing  its 
occurrence.  Its  avoidance  for  grain  crops,  while  im- 
portant, is  not  so  important  a  matter  as  in  the  case 
of  forage  crops,  since  an  extension  of  the  period  of 
growth  simply  delays  ripening,  while  in  the  latter, 
delays  not  only  prevent  maximum  growth  within  a 
certain    time,    but    seriously  interfere   with    rotations. 

Winter  oats,  which  are  successfully  grown  in  the 
southern  sections  of  the  country,  should  be  fertilized 
at  time  of  seeding  practically  in  the  same  manner  as 
wheat ;   that  is,  dressings  furnishing  small  amounts  of 


248  FERTILIZERS 

nitrogen  and  considerable  phosphoric  acid,  to  be  fol- 
lowed in  spring  with  a  top-dressing  of  nitrate  of 
soda,  not  to  exceed  100  pounds  per  acre. 

Oats   and   Peas 

Where  oats  are  grown  with  field  peas  for  the  pur- 
pose of  supporting  the  vines,  as  well  as  to  obtain  a 
larger  yield  than  from  either  alone,  the  fertilizer 
should  also  contribute  toward  the  increase  in  the 
pea  crop,  and  hence  a  greater  abundance  of  the 
minerals  should  be  applied,  though  it  is  very  desir- 
able in  this  case,  too,  to  encourage  the  rapid  growth 
of  the  oats  by  reasonably  liberal  supplies  of  available 
nitrogen. 

Barley  and   Peas 

The  growth  of  this  combination  of  plants  is  a 
desirable  one  when  late  fall  forage  is  needed,  and  as 
a  crop  is  well  adapted  for  fall  conditions.  The  ferti- 
lization should  be  liberal,  in  order  to  encourage  a 
rapid  and  large  appropriation  of  food,  which  may  be 
elaborated  after  light  frosts  occur.  An  application 
of  200  pounds  per  acre  of  a  mixture  of  100  pounds 
of  nitrate  of  soda,  175  of  acid  phosphate  and  25  of 
muriate  of  potash,  will  furnish  sufficient  and  good 
proportions  of  the  plant -food  constituents. 

Millet 

The  various  kinds  of  millet  are  eminently  sur- 
face feeders,  and  are  particularly  benefited  by  liberal 


THJE    FERTILIZATION    OF   MILLET  249 

applications  of  all  the  fertility  elements.  In  fact, 
maximum  forage  crops  of  this  plant  cannot  be  ob- 
tained except  when  there  is  present  in  the  soil  such 
an  abundance  of  all  of  the  fertility  elements  as  to 
enable  a  continuous  and  rapid  growth.  Both  the 
nitrogen  and  phosphoric  acid  should  be  largely  in 
immediately  available  forms;  hence  nitrates  and  super- 
phosphates are  recommended.  The  potash  may  be  in 
the  form  of  muriate.  A  crop  of  ten  tons  per  acre  of 
millet  forage,  of  any  of  the  Japanese  varieties,  which 
are  very  suitable  for  this  purpose,  will  remove  50 
pounds  of  nitrogen,  25  of  phosphoric  acid,  and  110 
of  potash,  practically  all  of  which  food  is  absorbed 
from  the  immediate  surface  soil.  Good  crops  fre- 
quently reach  this  assumed  yield ;  hence,  unless  the 
land  is  in  a  high  state  of  fertility,  or  has  been  pre- 
viously fertilized,  it  is  necessary,  in  order  to  obtain  a 
fair  crop,  to  furnish  by  direct  application  at  least  one- 
half  of  the  nitrogen  and  potash,  and  as  much  phos- 
phoric acid,  as  are  contained  in  the  crop.  These 
amounts  and  kinds  of  plant -food  could  be  practically 
supplied  by  a  dressing  of  450  pounds  of  a  mixture 
made  up  of  150  pounds  of  nitrate  of  soda,  200  of  acid 
phosphate,  and  100  of  muriate  of  potash,  and  such 
dressings  have  given  excellent  satisfaction  in  the 
New  Jersey  experiments  with  forage  crops. 

CLOVERS  AND  OTHER  LEGUMES 

These  are  among  the  most  valuable  of  our  summer 
forage    crops :     first,    because    of    the    time    of    their 


250  FERTILIZERS 

growth,  they  furnish  food  before  spring -sown  crops 
are  ready ;  second,  because  of  their  power  of  ac- 
quiring food  from  sources  inaccessible  to  the  cereals, 
they  are  less  exhaustive;  and  third,  they  are  espe- 
cially rich  in  the  compound  protein,  the  most  useful 
substance  contained  in  feeds.  Since  these  crops  gen- 
erally grow  well  on  soils  of  medium  fertility,  many  are 
inclined  to  regard  them  as  able  to  subsist  and  make  a 
good  crop  without  liberal  fertilization.  It  should  be 
remembered,  however,  that  the  power  which  these 
plants  possess  of  acquiring  nitrogen  from  the  air 
depends  largely  upon  the  supply  at  their  command  of 
the  mineral  elements,  phosphoric  acid,  potash  and 
lime  ;  the  presence  of  these  is  of  primary  importance, 
and  good  crops  cannot  be  grown  on  land  deficient  in 
these  elements.  In  any  event,  therefore,  liberal  sup- 
plies of  the  minerals  should  be  provided,  in  order  that 
maximum  yields  may  be  obtained.  On  soils  of  medium 
fertility  which  are  fairly  well  supplied  with  vegetable 
matter,  the  need  for  nitrogen  is  not  marked,  even  in 
the  early  growth  of  the  plant.  On  lighter  soils,  how- 
ever, a  nitrogenous  fertilization  is  often  serviceable, 
because  supplying  nitrogen  before  the  plant  has  ac- 
quired the  power  of  obtaining  it  from  the  air.  This 
practice  enables 'the  plant  to  make  an  earlj-  start,  and 
prevents  the  delay  in  growth  which  sometimes  occurs, 
particularly  on  light  soils,  during  the  period  imme- 
diately after  germination,  when  the  plant  is  unable  to 
obtain  its  nitrogen  from  sources  other  than  the  soil. 
A  green  forage  crop  averaging  10  tons  per  acre  re- 
quires, on  the  average,  about. 30  pounds  of  phosphoric 


I 


FKRTILIZEBS  FOR   SUMMER  LEGUMES  251 

acid  and  100  of  potash,  and  the  nitrogen  which  neces- 
sarily accompanies  these  amounts  of  minerals  will 
reach,  on  the  average,  100  pounds.  If  this  element  is 
drawn  from  the  air,  because  provided  with  an  abun- 
dance of  minerals,  it  is  manifestly  economy  to  supply 
the  full  amount  of  these  required,  rather  than  omit 
them,  and  thus  to  limit  the  plant's  power  of  acquiring 
this  expensive  element,  since  the  value  of  the  100 
pounds  of  nitrogen  gained  is  greater  than  the  cost  of 
both  the  phosphoric  acid  and  potash  required. 

Cow  Pea   and   Soy  Bean 

The  clovers,  which  range  in  their  length  of  life 
from  annuals  to  perennials,  are,  too,  able  to  obtain 
their  necessary  supplies  of  minerals  more  readily  from 
soil  sources  than  the  distinctly  summer  crops,  as  the 
cow  pea  and  soy  bean,  because  of  the  longer  period  of 
preparatory  growth  in  the  case  of  the  former.  That 
is,  clover  or  vetch,  while  it  does  make  a  very  rapid 
growth  through  a  short  period,  does  not  obtain  all 
of  its  food  during  that  period.  In  its  preparatory 
stage  of  growth — fall  and  early  spring — a  very  con- 
siderable amount  of  food,  the  larger  proportion,  in 
many  instances,  is  obtained,  which  in  its  later  stages 
of  growth,  is  simply  distributed  throughout  the  entire 
plant;  while  the  cow  pea  and  soy  bean,  on  the  other 
hand,  must  obtain  the  entire  amount  of  food  needed 
for  their  growth  and  development  during  a  short 
period,  and  these  crops  reach  their  best  stage  of 
development  for  forage  in  two  and  one -half  to  three 


252  FERTILIZERS 

months  from  time  of  planting.  Hence,  these  crops, 
which  possess  apparently  greater  foraging  powers,  and 
make  their  development  during  the  season  when  con- 
ditions are  most  favorable  for  rapid  change  of  in- 
soluble to  soluble  food  in  the  soil,  require,  when  the 
conditions  of  the  land  are  the  same  in  each  case,  a 
relatively  greater  abundance  of  the  mineral  elements 
than  do  the  clovers,  which  can  acquire  food  through 
a  longer  period. 

An  application  of  300  pounds  per  acre  of  a  mixture 
of  200  pounds  of  acid  phosphate  and  100  of  muriate 
of  potash,  which  supplies  25  pounds  of  phosphoric 
acid  and  50  of  potash,  would,  on  medium  soils,  be 
regarded  as  a  sufficient  annual  dressing  for  clover  crops ; 
whereas,  in  the  case  of  the  purely  summer  crops,  the 
application  could  be  increased  one -half  with  profit. 
In  the  case  of  the  summer  crop,  the  phosphoric  acid 
should  be  in  a  soluble  form,  because  it  is  not  economy 
to  depend  upon  the  conditions  of  climate,  soil  and 
season  to  change  insoluble  forms  rapidly  enough  to 
provide  for  the  continuous  feeding  of  the  plant,  while 
for  the  clovers,  less  available  forms  may  be  used  with 
advantage. 

Alfalfa,  or  Lucerne 

This  valuable  crop,  which  was  not  formerly  regarded 
as  well  adapted  for  the  eastern  states,  can  be  success- 
fully and  profitably  grown  if  the  soil  is  sufficiently 
deep  and  open  and  naturally  well  drained,  and  pro- 
vided  it   is   supplied   with    an   abundance   of    mineral 


ALFALFA   OB  LUCEBNE  253 

food,  consisting  of  phosphoric  acid,  potash  and  lime. 
Its  habits  of  growth  are  such  as  to  enable  the  harvest- 
ing of  three  or  four  green  forage  crops,  and  at  least 
two  hay  crops  annually.  In  order  to  meet  the  large 
plant -food  demands  thus  made,  the  fertilization  pre- 
vious to  seeding  must  be  not  only  liberal,  but  frequent 
top -dressings  should  be  made.  The  phosphoric  acid 
for  these  dressings  should  preferably  be  drawn  from 
superphosphates,  in  order  that  ready  distribution  may 
be  accomplished,  while  a  large  portion  of  that  con- 
tained in  the  preparatory  dressing  may  consist  of  the 
less  soluble  forms,  as  ground  bone,  natural  phosphatic 
guanos,  and  fine  ground  rock  phosphates. 

Twenty  tons  of  alfalfa  green  forage,  which  may  be 
regarded  as  a  good  annual  yield  for  this  plant  from  the 
two  to  four  cuttings  that  may  be  made,  will  contain 
250  pounds  of  nitrogen,  50  of  phosphoric  acid  and 
275  of  potash.  Assuming  that  the  demands  for  soil 
nitrogen  are  confined  to  a  short  period  immediately 
subsequent  to  the  germination  of  the  seed,  the  total 
required  plant -food  is  still  considerable,  and  is  es- 
pecially severe  upon  the  potash  compounds  of  the  soil. 
Hence,  the  fertilizers  supplied  should  be  particularly 
rich  in  this  element.  For  eastern  conditions,  where 
soils  possess  a  medium  rather  than  a  high  potential 
fertility,  heavy  dressings  of  the  minerals  should  always 
be  made.  A  good  preparatory  fertilizer  may  consist 
of  20  pounds  of  nitrogen,  equivalent  to  125  pounds 
of  nitrate  of  soda  ;  75  of  phosphoric  acid,  equivalent 
to  600  of  acid  phosphate  ;  and  200  of  actual  potash, 
equivalent   to   400    pounds    of   muriate  of   potash  per- 


254  FERTILIZERS 

acre ;  and  annual  top -dressings  should  provide  at 
least  30  pounds  of  phosphoric  acid  and  100  of  actual 
potash  for  the  same  area. 

Inasmuch  as  careful  preparation  of  soil  is  necessary 
previous  to  seeding,  and  since  this  can  preferably  be 
accomplished  by  the  growth  of  cultivable  crops,  the 
fertilizers  may  be  also  partly  applied  to  these  rather 
than  all  at  once  immediately  preceding  the  seeding, 
thus  limiting  danger  of  injury  to  germination  by  an 
application  of  so  large  a  proportion  of  salts. 

'Need   of  lAme  for   Legumes 

Another  point  that  should  be  remembered  in  the 
fertilization  of  the  leguminous  plants  is  their  need  for 
lime.  This  is  true  of  the  clovers  particularly,  not  only 
for  the  purpose  of  providing  the  plants  with  a  suf- 
ficient amount  of  this  element,  but  in  order  that  any 
possible  acidity  of  soil  may  be  corrected,  since  the  bac- 
terial life  in  the  soil,  which  is  essential  in  order  that 
the  plant  may  acquire  its  nitrogen  from  the  air,  is 
discouraged  rather  than  encouraged  by  the  presence  of 
acid.  Hence,  all  soils  that  are  used  for  the  frequent 
growth  of  leguminous  crops  should  receive  a  dressing 
of  lime,  preferably  in  the  fall ;  25  bushels  of  stone 
lime  per  acre,  once  in  four  or  five  years,  is  a  suf- 
ficient amount  for  medium  soils. 

The  necessity  for  fertilization,  and  the  method 
employed  in  "intensive"  practice,  are  illustrated  by  the 
following  scheme  of  growing  soiling  crops,  now  prac- 
ticed at  the  Experiment  Farm  in  New  Jersey.     If  an 


SOILING-CROP  ROTATION  255 

abundance  of  food  is  not  supplied,  the  continuous 
feeding  and  consequent  constant  and  rapid  growth  of 
the  plants,  which  are  primary  necessities  of  the  sys- 
tem in  order  to  maintain  the  rotation  and  to  obtain 
maximum  j'ields,  are  prevented.  With  proper  man- 
agement in  other  respects,  the  scheme  of  rotation  and 
fertilization  will  result  in  a  gradual  increase  in  the 
fertility  of  the  soil. 

Scheme   of  Soiling  Crops 

Nil.  of  Crop  Time  of  Amount  of  Time  of 

Acre         Rotation  Seeding  Fertilizer  Applied  Harvesting 

Crimson  Clover.  .Aug.  11,'97|  ^^^  ^^"-  ^"^  Phosphate      |  g^  ,gg 

>-   50  lbs.  Muriate  of  potash  > 

{100  lbs.  Acid  phosphate      ^ 
50  lbs.  Grouud  bone  ^Aug.  20/98 

50  lbs.  Muriate  of  potash  J 
r  25  lbs.  Nitrate  of  soda      ^ 
Barley  and  Peas.  .Aug.  25, '98-!  100  lbs.  Acid  phosphate       loct.  25,'98 
I  50  lbs.  Muriate  of  potash  J 

CriinsonClover..Aug.24,'97|12;;j'-^,"'^f«7^^*«      ^May  10,'98 
I  50  lbs.  Muriate  of  potash  J       ^ 

rlOO  lbs.  Acid  phosphate      •\ 

Corn Junel0,'98<    50  lbs.  Ground  bone  >Aug.  10,'98 

I  50  lbs.  Muriate  of  potash  J 

{25  lbs.  Nitrate  of  soda      -v 
100  lbs.  Acid  phosphate      I  Oct.  25, '98 
50  lbs.  Muriate  of  potash  J 

{50  lbs.  Nitrate  of  soda      1 
100  I,bs.  Acid  phosphate 
50  lbs.  Ground  bone 
50  lbs.  Muriate  of  potash  J 
{75  lbs.  Nitrate  of  soda     -j 
150  lbs.  Acid  phosphate       I  Oct.    1,  '98 
75  lbs.  Muriate  of  potash-* 


256  FERTILIZERS 

No.  of  Crop      "         Time  of  Amount  of  Time  of 

Acre         Botatum  Seeding  Fertilizer  Applied  Harvestirtg 


f  50  lbs.  Nitrate  of  soda     "I 

I    50  lbs.  Ground  bone 

(.  50  lbs.  Muriate  of  potash 


«-.  TIT       1ft  loo     100  lbs.  Acid  phosphate         ,   ,     ,„  ,„„ 

Corn May  10,  98<    _  ^  l-July  10/98 


{25  lbs.  Nitrate  of  soda     -v 
100  lbs.  Acid  phosphate      I  Oct.    10,'98 
50  lbs.  Muriat«  of  potash  J 


5i 


150  lbs.  Acid  phosphate     ^ 

Wheat Sept.  28, '97 ■{    50  lbs.  Ground  bone  J-.June 

25  lbs.  Muriate  of  potash ' 


iJ 


!25  lbs.  Nitrate  of  soda     1 
100  lbs.  Acid  phosphate        j^^^  ^^,^^ 
2o  lbs.  Ground  bone  I 

50  lbs.  Muriate  of  potash  J 

en  t         1    ,„„  r  200  lbs.  Acid  phosphate     \r>  *    ■,    mo 

S°y^«^« ^"^-  1'  ^n  100  lbs.  Muriate  of  potash  I  ^^*-   ''    '' 

{150  lbs.  Acid  phosphate     -» 
50  lbs.  Ground  bone  I  May   1,  '98 

25  lbs.  Muriate  of  potash  J 

r  75  lbs.  Nitrate  of  soda      \ 

Millet May  1,  '98-1  150  lbs.  Acid  phosphate      i-July   1,  '98 

I  75  lbs.  Muriate  of  potash  J 

„       T>  T  1     tin  ino  f  200  lbs.  Acid  phosphate      To     .  „„  ,__ 

Cow  Peas July  20,  98 ^  , „„  ,^     „     .\      ^     ^    ,> Sept. 20, '98 

*■  1. 100  lbs.  Muriate  of  potash  J      *^ 

(25  lbs.  Nitrate  of  soda      I 
100  lbs.  Acid  phosphate      I  j^^^  io,'98 
25  lbs.  Ground  bone 
50  lbs.  Muriate  of  potash  J 

SoyBeans July  j^ -ggj  200  lbs.  Acid  phosphate      jgept.  i, -93 

1 100  lbs.  Muriate  of  potash  J 


potash  - 
25  lbs.  Nitrate  of  soda      -> 

—   '  r 

50  lbs.  Muriate  of  potash  J 


Barley  and  Peas..  Sept.  1,  '98-1  100  lbs.  Acid  phosphate      |-Nov.  1,  '98 


FERTILIZERS  FOR  ROOT  CROPS 


257 


No.  of 
Acre 


Crop 
Rotation 


Time  of 
Seeding 


Oats  and  Peas... April  1/98 


Amount  of 
Fertilizer  Applied 

25  lbs.  Nitrate  of  soda 
100  lbs.  Acid  phosphate 
25  lbs.  Ground  bone 


Time  of 
Harvesting 

I  June  1,  '98 


50  lbs.  Muriate  of  potash  J 

Cow  Peas June  15,'98|20;  J^^-  :f  «^d  phosphate      | 

1100  lbs.  Muriate  of  potash  J 


98 


Barley  and  Peas. .Aug.  20,'98-|  100  lbs.  Acid  phosphate      |-Oct.  20,  '98 
L  50  lbs.  Muriate  of  potash  J 


Rye  and  Vetch.. .Sept.  10, '97 


25  lbs.  Nitrate  of  soda      ^ 
150  lbs.  Acid  phosphate      >May  5,  '98 
75  lbs.  Muriate  of  potash  J 

■  100  lbs.  Acid  phosphate 


Com June 


r  luu  IDS.  Acm  pnospnate     ~v 

5<    50  lbs.  Ground  bone  >j 

I   50  lbs.  Muriate  of  potash  J 

25  lbs.  Nitrate  of  soda 


l,'£ 


Barley  and  Peas.  .Aug.  15,'98^  100  lbs.  Acid  phosphate      loct.  15,  '98 
V.  50  lbs.  Muriate  of  potash  J 


This  scheme,  which  provides  for  two  or  three 
crops  each  season,  has  proved  entirely  practicable 
and  successful  when  liberal  fertilization  is  practiced, 
as  here  indicated. 


ROOT   CROPS 

These  crops  are,  as  a  class,  exhaustive  of  plant- 
food  elements,  much  more  so,  in  proportion  to  the  dry 
matter  contained  in  them,  than  the  cereals  or  legumes. 
It  will  require,  for  example,  20  tons  of  topped  fodder 
beets  or  turnips  to  furnish  as  much  total  food  as  is 
contained  in  10  tons  of   corn  forage  or  silage,  as  the 


258  FEBTILIZERS 

former  seldom  contain  more  than  10  per  cent  of  dry 
matter,  whereas  the  latter  frequently  contain  more  than 
20  per  cent ;  yet  on  the  average,  20  tons  of  roots  will 
contain  60  pounds  of  nitrogen,  equivalent  to  400 
pounds  nitrate  of  soda,  35  of  phosphoric  acid,  equiva- 
lent to  300  pounds  of  acid  phosphate,  and  150  of 
potash,  equivalent  to  300  of  muriate  of  potash,  which 
amounts  are  far  in  excess  of  those  contained  in  a  corn 
crop,  particularly  of  the  minerals,  phosphoric  acid  and 
potash.  The  nitrogen  demands  for  the  two  crops  are 
practically  identical.  In  the  case  of  both  kinds  of 
crops,  these  fertility  constituents  are  obtained  entirely 
through  the  roots  from  soil  sources. 

In  respect  to  fertilization,  however,  the  root  crops 
may  be  divided  into  two  groups,  very  similar  in  their 
demands  for  plant -food,  the  first  to  include  mangel- 
wurzels,  fodder  beets,  sugar  beets  and  carrots,  and  the 
second  turnips,  swedes  (ruta-bagas)  and  rape. 

Fertilizers  for  Fodder  Beets,  Sugar   Beets  and    Carrots 

The  first  group  requires  that  the  fertilization  with 
nitrogen  and  phosphoric  acid  shall  be  liberal,  and  that 
these  constituents  shall  be  applied  in  readily  soluble 
forms,  in  order  to  meet  the  large  and  early  demands  of 
the  plant  for  them.  Potash  is  also  a  very  essential 
constituent,  particularly  upon  soils  of  a  light,  sandy 
character ;  upon  clay  loams,  the  plant  is  better  able  to 
obtain  this  element. 

In  order  to  obtain  a  large  amount  of  actual  food  by 
the  growth  of   these   crops,  a   large  tonnage  must   be 


foddeh  beets,  sugar  beets,  carrots     259 

secured,  and  a  large  yield  cannot  be  obtained  unless 
provision  is  made  for  a  continuous  and  rapid  growth, 
and  this  again  cannot  be  accomplished  without  an 
abundant  supply  of  nitrogen  and  phosphoric  acid, 
which,  as  already  stated,  are  the  elements  which,  more 
than  any  others,  seem  to  rule  the  crop. 

In  the  case  of  sugar  beets,  the  suggestion  for  fer- 
tilization when  grown  for  sugar  (Chap.  XI),  may  be 
followed  in  large  part.  That  is,  particular  attention 
should  be  given  to  the  supply  of  nitrogen  and  phos- 
phoric acid,  though  when  grown  for  forage  it  is  im- 
portant not  only  to  secure  sugar,  which  constitutes  a 
large  proportion  of  the  dry  matter,  but  that  the  gross 
yield  shall  be  much  greater  than  in  the  former  case. 
Hence,  a  liberal  use  of  yard  manure  need  not  be 
avoided,  and  heavier  dressings  of  nitrogen,  which 
stimulates  early  leaf  growth,  may  be  made. 

For  both  fodder  beets  and  sugar  beets,  an  applica- 
tion per  acre  of  40  pounds  of  nitrogen,  50  of  phos- 
phoric acid  and  100  of  potash,  or  1,000  pounds  of  a 
fertilizer,  containing — 

Nitrogen 4  % 

Available  phosphoric  acid b  % 

Potash 10% 

should  insure  a  very  considerable  increase  in  yield  on 
soils  of  medium  fertility,  provided  the  elements  are 
drawn  from  the  best  materials.  On  light  soil  the  fer- 
tilization should  be  still  heavier,  and  the  proportion 
of  nitrogen  increased.  In  fact,  on  soils  poor  in  fer- 
tility and  possessing  good  physical  qualities,  the  con- 


260  FEBTILIZEBS 

tributions  of  plant -food  by  tbem  may  be  largely  ig- 
nored, and  the  dressings  made  large  enough  to  supply 
the  entire  amount  of  food  required  by  the  crop.  On 
such  soils  the  nitrogen  should  preferably  be  applied  in 
fractional  di'essings  and  in  quickly  available  forms, 
because  it  is  essential  that  this  element  should  be 
quickly  absorbed  by  the  growing  plant.  The  minerals 
may  be  all  applied  in  one  dressing,  though  preferably 
in  two,  in  order  that  the  constituents  may  be  well 
distributed  throughout  the  surface  soil.  To  better 
accomplish  this,  cultivation  should  follow  each 
application. 

Turnips,  Stvedes  and  Rape 

In  the  case  of  the  second  class  of  crops,  it  has 
been  shown  that  they  are  able  to  extract  their  phos- 
phoric acid  from  combinations  not  readily  accessible 
to  other  plants.  In  fact,  they  respond  so  promptly  to 
applications  of  this  element,  that  frequently  too  little 
attention  is  given  to  the  supplies  of  the  other  elements ; 
yet  in  order  to  obtain  satisfactory  yields,  these  must 
also  be  added.  An  analysis  of  the  turnip,  for  example, 
shows  it  to  be  rich  in  potash;  hence  it  must  naturally 
be  a  voracious  feeder  upon  compounds  containing  this 
element,  and  while  it  seems  to  obtain  it  more  readily 
from  soil  sources  than  many  other  plants,  these  sup- 
plies should  not  be  depended  upon,  even  on  good  soils, 
to  meet  its  entire  needs  in  this  respect.  A  liberal 
supply  of  nitrogen  is  also  demanded,  particularly  dur- 
ing the  early  growth.     An  application  of   a  fertilizer 


TUBNIPS,  SWEDES  AND  BAPE  261 

containing  20  pounds  of  nitrogen,  derived  in  part 
from  nitrate,  40  of  phosphoric  acid,  derived  in  large 
part  from  phosphates,  and  40  of  potash,  derived  from 
muriates,  would  be  a  fair  dressing  on  soils  of  good 
character.  On  the  poorer  soils,  the  application  of  the 
constituents  of  the  same  kind  and  forms  should  be 
very  largely  increased. 

In  these  crops,  as  in  those  already  mentioned,  it  is 
essential — and  success  depends  upon  this  as  much  as 
upon  any  other  factor — that  the  growth  should  be  con- 
tinuous ;  and  in  order  that  there  shall  be  no  delay  in 
this  respect,  there  must  be  an  abundance  of  available 
food  always  at  their  command. 

TUBER    CROPS 

In  many  sections  the  potato  and  sweet  potato  are 
grown  for  roughage.  For  these  crops  no  different 
fertilization  is  recommended  than  that  already  outlined 
(Chapter  XI)  for  the  crops  when  grown  for  market, 
though  in  the  case  of  sweet  potatoes,  soils  not  adapted 
for  the  growth  of  marketable  tubers  may  be  used. 


CHAPTER  XIII 

MARKET- GARDEN  CROPS 

A  KNOWLEDGE  of  the  principles  of  plant  nutrition 
is  perhaps  more  serviceable  in  market -gardening  than 
in  any  other  line  of  farming.  This  branch  of  farming 
cannot  be  profitably  conducted  either  without  suitable 
soils  or  without  an  abundant  supply  of  plant -food. 
Both  of  these  conditions  are  essential  for  the  growth 
of  high -class  products. 

THE      YIELD      AND      QUALITY      DEPENDENT      UPON 
CONTINUOUS  AND   RAPID   GROWTH 

In  these  days,  it  is  not  only  the  yield  of  a  definite 
area  that  must  be  considered,  but  the  edible  quality  of 
the  products  that  are  put  upon  the  market.  Quality 
depends  upon,  or  is  measured  by,  both  appearance  and 
palatability ;  and  palatability  is  determined  by  the 
succulence  and  sweetness  of  the  vegetable,  or  its  free- 
dom from  bitterness,  stringiness,  and  other  undesirable 
characteristics  which  frequently  exist,  and  which  can 
be  largely  eliminated,  provided  the  grower  is  thoroughly 
familiar  with  his  business,  assuming,  of  course,  that 
varieties  are  the  same  in  each  case.  It  has  been  dem- 
onstrated that  market -garden  crops  of  the  best  quality 
are   those   which   are   grown    under   conditions   which 

(262) 


\ 


FKBTILIZATION  IMPROVES   QUALITY  263 

permit  of  a  continuous  and  rapid  development.  Any 
delay  in  the  growth  of  a  radish  or  of  lettuce  is  largely 
responsible  for  the  sharp  taste  and  pungent  flavor  of 
the  former,  and  the  bitterness  and  toughened  fiber  of 
the  latter.  The  same  principles  hold  true  of  early 
table  beets  and  turnips.  The  beets  become  stringy  and 
wiry  in  character,  and  are  less  palatable  if  during  the 
period  of  normal  growth  there  has  been  any  delay.  In 
a  time  during  which  there  has  been  no  progress  the 
fibrous  portion  of  the  vegetable  is  toughened,  and 
exists  in  too  great  proportion.  In  the  case  of  the 
early  turnip,  if  any  delay  in  growth  occurs,  the  quality 
is  injured,  and  the  peculiar,  pleasant  flavor,  a  charac- 
teristic of  the  perfect  vegetable,  is  changed  ;  it  becomes 
unpleasant.  The  unfavorable  conditions  of  growth 
seem  to  cause  more  or  less  reversion  to  the  character 
of  the  original  plant  from  which  the  improved  type 
has  been  derived,  mainly  through  selection  and  im- 
proved methods  of  cultivation. 

All  these  conditions  of  growth  are  not  absolutely 
under  the  control  of  the  grower ;  as,  for  example,  a 
lack  of  Bufiicient  moisture  and  sunshine,  the  latter  of 
which  is  certainly  beyond  his  power  to  control.  But 
given  good  natural  conditions  in  respect  to  soil,  and  a 
favorable  season,  the  one  thing  that  more  than  any 
other  controls  the  yield  and  quality  of  market -garden 
products  is  plant-food  of  the  right  amount  and  kind. 
In  other  words,  in  crops  of  this  sort,  any  limitation  in 
this  respect  usually  results  in  a  disproportionate  re- 
duction in  profits.  Only  under  exceptional  circum- 
stances is   it  economical  to  depend  upon  natural   soil 


264  FERTILIZERS 

conditions  for  profitable  crops,  however  favorable  such 
conditions  may  be,  because  in  successful  practice  the 
cropping  is  in  the  highest  degree  "intensive,"  and  even 
the  best  soils  are  liable  to  be  deficient  in  some  essen- 
tial feature. 

It  might  seem  from  the  discussion  thus  far,  that  for 
these  crops  the  recommendations  as  to  methods  of 
fertilization  might  be  briefly  though  fully  expressed 
as  follows  : 

Apply  a  reasonable  excess  of  all  of  the  essential 
fertilizer  constituents  to  all  of  the  crops.  Neverthe- 
less, because  of  the  peculiarities  of  growth  of  the 
different  plants,  as  well  as  the  different  objects  of  their 
growth,  distinctions  should  be  made  in  reference  to  the 
kinds  and  amounts  of  plant -food  applied,  and  these 
distinctions  should  be  borne  in  mind,  in  order  that  the 
most  profitable  returns  may  be  secured.  Market -gar- 
den crops  may,  however,  be  grouped  according  to 
similarity,  both  in  character  and  object  of  growth, 
and  each  group  fertilized  in  a  similar  manner,  which 
obviates  the  necessity  of  extra  labor  in  the  preparation 
of  fertilizers. 

ASPARAGUS 

Asparagus  is  one  of  the  very  important  vegetable 
crops,  and  perhaps  no  other  renders  so  profitable  a 
return  for  proper  manuring  and  fertilizing.  It  differs 
from  the  majority  of  the  others  in  two  essential  par- 
ticulars. First,  it  is  a  perennial,  the  length  of  life 
of   a  bed  depending  largely  upon  the  treatment;    and 


FERTILIZERS  FOR  ASPARAGUS  265 

second,  only  one  crop  can  be  obtained  in  a  season — it 
occupies  the  land  to  the  exclusion  of  other  crops. 
Hence,  special  efforts  should  be  made  to  obtain  as 
large  a  crop  as  the  conditions  of  season  and  climate 
will  permit.  With  this  plant  the  yield  and  market 
quality  of  the  crops  depend  upon  the  number  and  size 
of  the  shoots.  In  respect  to  quality,  the  demands  of 
the  different  markets  vary.  Some  of  them  require  that 
the  shoots  shall  be  bleached  and  so  cut  as  to  present 
only  a  green  tip,  the  remainder  being  perfectly  white, 
while  others  demand  that  the  shoot  shall  be  green. 
But  in  both  cases,  the  size  of  the  shoot  determines 
salability,  and  the  size  is  largely  measured  by  the 
methods  observed  in  feeding  the  plant  when  other 
conditions  are  favorable ;  that  is,  if  not  injured  by 
disease  or  insects.  Small,  spindling  shoots  usually 
indicate  that  the  crop  has  not  been  well  cared  for,  or 
that  the  plant  has  been  imperfectly  nourished. 

The  root  is  enlarged  and  invigorated  by  the  char- 
acter of  the  growth  of  the  tops,  or  summer  growth  of 
the  plant  after  cutting  is  finished,  and  it  is  obvious 
that  the  manuring  should  be  such  as  to  encourage  not 
only  a  rapid  growth  of  shoots  early,  but  a  large  and 
vigorous  growth  of  tops  later,  which  assists  the  growth 
of  the  roots  in  which  energy  is  stored  up  for  the  pro- 
duction of  the  crop  in  the  following  year.  Hence, 
not  only  the  character  but  the  method  of  fertilization 
is  important,  and  it  differs  from  that  recommended 
for  those  plants  which  grow  from  the  seed  in  one 
season  and  which  must  depend  upon  what  they  are 
able  to  acquire  during  their  short  period  of  growth. 


266  FERTILIZERS 

The  Use  of  Salt 

It  was  formerly  believed  that  one  of  the  most 
important  ingredients  of  manures  for  the  asparagus 
plant  was  common  salt,  and  that  in  any  fertilization 
this  substance  should  occupy  a  prominent  part. 
Experience  has  shown,  however,  that  while  salt  may 
not  be  harmful,  there  is  no  real  fertility  value  in  it. 
The  crop  may  be  profitably  grown  without  its  appli- 
cation, though  it  does  no  harm,  and  there  is  no  objec- 
tion to  its  use  except  on  the  ground  that  it  adds  no 
essential  fertility  element,  and  its  indirect  benefit  may 
be  obtained  more  cheaply  by  the  use  of  other  ma- 
terials, which  contain  salt  as  a  normal  ingredient, — 
for  example,  kainit,  the  crude  potash  salt,  which  is 
one-third  salt,  though  its  market  price  is  based  solely 
upon  its  potash  content. 

Fertilizers   that  Have   Proved    Useful 

Fertilizers  which  have  been  found  very  useful  for 
asparagus  are  those  which  contain  food  both  in  im- 
mediately available  and  in  gradually  available  forms. 
During  the  early  growing  season,  the  available  food 
may  be  appropriated  rapidly  enough  to  cause  an  in- 
crease in  the  yield  of  shoots  of  that  year ;  and  inas- 
much as  the  plant  continues  to  grow  until  winter,  the 
food  that  becomes  gradually  available  is  appropriated 
later,  and  contributes  to  the  strength  and  vigor  of 
the  roots  upon  which  the  next  year's  crops  depend. 
Furthermore,    because   the   crop   is  gathered  from  the 


USE   OF  A    BASIC   FORMULA  267 

early  shoots,  which  are  continuously  removed  for 
from  one  to  two  months,  the  root  is  continuously 
drained  of  its  stored -up  material,  and  at  the  end  of 
the  cutting  season  it  has  been  very  much  reduced  in 
vitality ;  wherefore  it  is  particularly  desirable  that 
available  food  be  applied  at  this  time  also,  in  order 
to  encourage  a  rapid  and  vigorous  growth  of  the 
top,  which  aids  in  the  storing  up  of  food  in  the 
root.     A  fertilizer  containing  — 

Nitrogen 4  ^ 

Phosphoric  acid 8  % 

Potash 10  % 

the  nitrogen  to  be  drawn  from  both  soluble  and 
organic  sources,  and  the  phosphoric  acid  from  both 
superphosphate  and  ground  bone,  or  tankage,  and  the 
potash  from  muriate,  may  be  applied  previous  to  set- 
ting the  crowns,  at  the  rate  of  1,000  to  1,500  pounds 
per  acre,  and  thoroughly  worked  into  the  soil. 

A   Basic  Fertilizer  for  Market -garden    Crops 

For  market -garden  crops,  a  fertilizer  of  the  above 
composition  may  be  regarded  as  a  basic  mixture,  which 
may  be  applied  to  all  of  the  crops,  leaving  the  specific 
needs  of  the  different  plants  to  be  met  by  top -dress- 
ings, or  applications  of  the  other  constituents.  The  ferti- 
lizer ingredients,  nitrogen  and  phosphoric  acid,  should 
preferably  consist  of  the  different  forms,  rather  than 
to  be  all  of  one  form,  though  the  cost  of  the  element 
will    naturally    regulate    this    point    to    some    extent. 


268  FERTILIZERS 

That  is,  a  part  of  the  nitrogen  should  be  nitrate  or 
ammonia,  and  a  part  organic ;  a  part  of  the  phos- 
phoric acid  should  be  soluble  (from  superphosphates), 
and  a  part  insoluble  (from  ground  bone,  tankage  or 
natural  phosphates).  The  soluble  portions  of  both 
nitrogen  and  phosphoric  acid  contribute  to  the  im- 
mediate needs  of  the  plant,  and  the  less  soluble  to 
its  continuous  and  steady  growth,  and  to  the  poten- 
tial fertility  of  the  soil. 

For  asparagus,  this  basic  fertilizer  may  be  applied 
at  this  same  rate, — 1,000  to  1,500  pounds  per  acre, — 
at  the  time  of  setting  the  crowns,  or  even  in  greater 
amounts  from  year  to  year,  preferably  early  in  the 
spring,  in  order  that  the  plant  may  have  the  whole 
season   for   the  appropriation  of   the   food. 

The  specific  fertilizer,  in  addition,  should  contain 
immediately  available  forms  of  food,  and  should  be 
applied  preferably  immediately  after  or  during  the 
latter  period  of  the  cutting,  in  order  to  feed  at  once, 
and  thus  stimulate  and  strengthen  the  plant  in  its 
condition  of  lowered  vitality,  due  to  the  continuous 
and  large  removal  of  the  shoots.  This  application 
should  also  be  liberal,  since,  as  already  indicated, 
limitations  at  this  time  may  result  in  a  greatly  de- 
creased yield  and  a  poorer  quality  of  product  the 
next  year,  and  hence  a  reduction  in  profit.  The  best 
growers  apply,  in  addition  to  the  fertilizer  recom- 
mended, and  after  cutting,  not  less  than  250  pounds 
of  nitrate  of  soda,  300  of  superphosphate,  and  muri- 
ate of  potash,  or  kainit,  equivalent  to  100  pounds  of 
actual  potash. 


I 


FERTILIZERS   FOR  PEAS   AND   BEANS  269 

These  recommendations  as  to  the  amounts  of  fer- 
tilizers may  seem  rather  large  to  those  who  have 
been  accustomed  to  light  applications,  but  they  are 
the  minimum  rather  than  the  maximum  amounts,  as 
many  growers  have  learned  that  the  extra  amounts 
applied  are  preferable  to  the  smaller  amounts,  con- 
tributing not  only  to  the  length  of  life  of  the  plant, 
but  also  to  the  total  yield  and  size  of  the  shoots,  as 
well  as  to  their  edible  quality,  which  is  measured  by 
their   succulence    and   flavor. 

These  suggestions  as  to  fertilizers  are  for  condi- 
tions where  large  amounts  of  organic  or  natural  ma- 
nures are  not  readily  obtainable.  When  these  are 
used,  they  may  serve  instead  of  the  basic  fertilizer, 
but  cannot  well  substitute  the  special  applications 
of  artificial  fertilizers  made  after  cutting  is  finished. 

PEAS    AND    BEANS 

Peas  and  beans  of  the  various  kinds  and  varieties 
belong  to  the  legume  family,  and  possess  the  power 
of  acquiring  nitrogen  from  the  air  ;  they  are,  therefore, 
ordinarily  placed  in  a  separate  class  in  respect  to  their 
fertilization  with  nitrogen.  When  they  are  grown  as 
market- garden  crops,  however,  it  is  frequently  the 
wiser  economy  to  apply  nitrogen,  particularly  if  they 
are  raised  upon  land  which  has  not  been  previously 
planted  with  these  crops,  and  thus  may  not  possess 
the  specific  nitrogen-gathering  bacteria :  because  it  is 
imperative  that  the  plants  should  not  only  have  an 
abundance  of   all    of   the   food   constituents,  but   that 


270  FERTILIZERS 

their  food  should  be  such  as  to  cause  as  long  a  crop- 
ping period  as  possible,  and  nitrogen  will  contribute 
to  this  end.  Hence,  in  the  fertilization  of  these  crops, 
while  the  minerals  are  the  primary  constituents  needed, 
nitrogen  should  also  be  applied,  and  it  should  prefer- 
ably be  in  the  organic  forms,  which  encourage  a  longer 
period  of  growth,  rather  than  in  the  single,  active- 
form  nitrate,  more  generally  recommended  for  the 
quick -growing  market -garden  crops,  because  its  com- 
plete solubility  and  immediate  availability  encourage 
a  rapid  growth  and  short  period  of  development.  The 
basic  fertilizer  recommended,  if  applied  at  the  rate 
of  500  to  600  pounds  per  acre,  will  usually  furnish 
sufficient  nitrogen,  and  may,  if  necessary,  be  supple- 
mented by  the  application  of  amounts  of  superphos- 
phate and  potash  salts  which  will  add  from  20  to  30 
pounds  of  phosphoric  acid,  and  60  to  75  of  potash. 

BEETS  AJID  TURNIPS 

The  early  table  beet  and  the  early  turnip  are  very 
important  market -garden  crops.  Wherever  gi-own, 
whether  in  the  South  for  the  northern  market,  or  in  the 
middle  states  for  the  near-by  market,  earliness  is  a 
primary  consideration  ;  and  the  earliness  of  the  crop  is 
determined  largely  by  the  amount  and  availability  of 
the  nitrogen  and  phosphoric  acid  applied.  These  are 
the  two  elements  which,  more  than  any  others,  modify 
and  dominate  the  growth  of  these  plants,  and  con- 
tribute to  their  profitable  production  as  early  market- 
garden  crops.     In  the   case  of   early  turnips   particu- 


EABLT  BEETS  AND   TURNIPS  271 

larly,  a  difference  of  two  or  three  days  in  the  begin- 
ning of  the  harvest  will  often  determine  the  profit  or 
loss  upon  the  crop.  The  experience  of  many  growers 
confirms  the  view  that  for  no  other  crop  is  the  necessity 
for  right  fertilization  more  important.  Since  the  early 
growth  of  these  crops  takes  place  before  active  nitrifi- 
cation begins  in  the  soil,  dependence  for  this  element 
must  be  placed  upon  the  nitrogen  applied,  and  it  is 
desirable  not  only  that  the  soils  should  be  well  supplied 
at  the  time  of  planting  with  all  of  the  constituents, 
but  that  frequent  top -dressings  of  the  soluble  nitrate 
shall  be  made.  Top -dressings  are  recommended  be- 
cause the  application  of  a  sufficient  amount  of  the 
nitrogen  in  this  form  at  the  time  of  seeding  might 
result  in  its  considerable  loss,  since  at  this  season  rains 
often  occur  which  are  frequently  so  heavy  as  to  cause 
a  leaching  of  the  nitrates  into  the  drains  or  into  the 
lower  layers,  and  thus  prevent  the  continuous  feeding 
of  the  plant,  and  a  consequent  delay  in  growth. 

An  application,  therefore,  of  from  1,000  to  1,500 
pounds  of  a  high-grade  fertilizer,  one  of  the  compo- 
sition of  the  basic  fertilizer  already  suggested  (p.  267), 
is  frequently  employed  at  the  time  of  seeding,  followed 
by  a  top-dressing  of  from  50  to  100  pounds  of  nitrate 
of  soda  per  acre  once  every  week  or  ten  days,  for  at 
least  three  or  four  weeks  after  the  plants  have  well 
started.  It  will  meet  the  requirements  for  added  fer- 
tility. Such  a  practice,  under  average  seasonal  condi- 
tions, insures  a  continuous  and  rapid  growth,  and  ob- 
viates to  some  extent  the  dangers  liable  to  follow  from 
too  much  ra\n  or  from  drought.    The  frequent  applica- 


272  FERTILIZERS 

tions  prevent  losses  from  leaching  if  heavy  rains  follow, 
and,  except  in  case  of  excessive  and  prolonged  drought, 
the  nitrate  remains  in  solution,  and  is  ready  to  be 
immediately  absorbed  by  the  plant.  The  advantage  of 
earliness  which  is  gained  by  the  use  of  apparently 
excessive  amounts  of  nitrogen  is  two -fold:  a.  higher 
price  is  received  for  the  product,  and  the  cost  of  labor 
per  unit  of  income  is  less.  Quite  as  large  yields  may 
be  obtained  by  smaller  dressings,  but  the  net  [in- 
come is  reduced  as  the  time  necessary  for  the  growth 
of  a  Tnarketable  beet  or  turnip  is  increased.  See  also 
Chapter  XII,  in  reference   to  this  subject. 

CABBAGE,  CAULIFLOWER  AND  BRUSSELS  SPROUTS 

These  large-leaved  plants  are  all  voracious  feeders, 
and  are  specifically  benefited  by  large  applications  of 
nitrogen  and  of  phosphoric  acid.  Heavy  applications 
of  the  basic  fertilizer  (p.  267),  which  is  excellent, 
should  be  supplemented  upon  good  soils  with  additions 
of  nitrogen  and  phosphoric  acid,  and  upon  light  soils, 
potash  may  also  be  added.  Notwithstanding  the  fact 
that  these  crops  are  particularly  benefited  by  nitrogen, 
the  character  of  the  edible  portion  or  head  of  the  dif- 
ferent plants  is  very  largely  influenced  by  the  nature  of 
the  growth.  Too  rapid  an  early  growth,  due  to  an  ex- 
cess of  nitrogen,  frequently  results  in  an  abnormal  de- 
velopment of  leaf,  which  is  not  accompanied  by  a 
proper  formation  of  the  head ;  hence  a  part  of  the 
nitrogen  essential  for  the  growth  of  the  plant  after  the 
head  has  begun  to  form  should  be  applied  at  this  time 


FEBTILIZEBS   FOB  MELONS  273 

in  an  immediately  available  form,  and  a  part  in  forms 
which  will  gradually  feed  the  plant.  A  good  method  of 
fertilization,  in  addition  to  the  application  of  from 
1,000  to  1,500  pounds  per  acre  of  the  basic  fertilizer, 
therefore,  may  consist  of  a  top-dressing  of  100  pounds 
of  nitrate  of  soda  and  200  of  superphosphate  per 
acre,  after  the  plants  have  begun  to  make  growth  after 
transplanting.  After  the  heads  begin  to  form,  another 
top-dressing  of  200  pounds  of  nitrate  of  soda  may  be 
applied,  which  will  contribute  toward  a  rapid  and 
continuous  growth  of  head,  provided  an  abundance  of 
the  minerals  is  present,  as  already  indicated, 

A  number  of  crops  belonging  to  this  group  of 
plants  require,  in  addition  to  a  sufficient  supply  of 
plant -food,  peculiar  climatic  conditions  for  their  best 
crop  development.  Caulitlower,  particularly,  not  only 
seems  to  be  so  influenced,  but  great  skill  and  expe- 
rience are  required  on  the  part  of  the  grower.  It 
must  be  remembered,  that  while  proper  fertilization  is 
essential,  it  is  only  one  of  the  primary  conditions  of 
successful  culture. 

CUCUMBERS,  WATERMELONS,  MUSKMELONS,  PUMPKINS 
AND  SQUASHES 

All  these  belong  to  one  botanical  group  of  plants, 
and  are  usually  adapted  for  similar  climatic  and  soil 
conditions,  though  watermelons  and  muskmelons  of 
good  quality  are  successfully  grown  only  upon  light, 
warm,  sandy  soils.  The  pumpkins,  cucumbers  and 
squashes  may  be  readily  grown  to  perfection  upon  the 


274  FERTILIZERS 

colder  and  more  compact  clayey  soils.  All  of  these 
crops  seem  to  require  an  abundance  of  vegetable  matter 
in  the  soil,  in  order  to  make  their  best  growth.  Hence, 
upon  soils  deficient  in  this  respect,  manures  should  be 
applied  which  are  rich  in  vegetable  matter.  Composts 
in  the  hill  have  proved  of  especial  advantage,  as  they 
seem  to  encourage  an  immediate  feeding,  and  prevent 
delay  in  early  growth.  In  the  best  growth  of  these 
plants  it  is  also  necessary  that  the  mineral  elements 
shall  be  available,  and  that  the  nitrogen  shall  be  of 
such  a  character  as  to  encourage  a  continuous  rather 
than  a  quick  growth  of  vine.  That  is,  unless  the 
quick -acting  nitrates  are  applied  very  frequently,  they 
are  less  desirable  than  organic  forms  of  nitrogen. 
Hence,  with  the  usual  broadcast  application  of  the 
basic  mixture  at  the  time  of  planting,  together  with  a 
compost  in  the  hill,  further  applications  of  organic 
nitrogen  should  be  made,  its  character  to  be  such  as  to 
promise  a  relatively  rapid  change  into  nitrate.  The 
basic  mixture  may  be  re -enforced  by  any  one  of  the 
following  materials:  200  to  300  pounds  per  acre  of 
cotton -seed  meal,  100  to  200  of  dried  blood,  or  300  to 
400  pounds  of  fine -ground  tankage.  Any  organic  sub- 
stance whose  greater  part  will  decay  in  one  season  will 
generally  give  better  results  than  the  nitrate,  unless 
the  latter  is  applied  in  frequent  small  top -dressings, 
because  organic  forms  of  nitrogen  provide  for  a  con- 
tinuous growth  of  vine  and  fruit,  while  too  great  an 
abundance  of  immediately  available  nitrogen  as  nitrate 
is  liable  to  cause  too  rapid  and  large  growth  of  fruit 
of    poor  quality.     This  does  not  apply  in  the  case  of 


FERTILIZER  FOR   CELERY  275 

cucumbers  for  pickling,  where  a  large  setting  of  im- 
mature fruits  is  desired.  In  this  case,  nitrogen  in  the 
form  of  a  nitrate,  if  properly  applied,  will  contribute 
to  a  large  setting  and  a  rapid  growth  of  the  fruits. 

CELERY 

Celery  is  another  plant  that  luxuriates  in  a  soil 
rich  in  vegetable  matter,  though  the  peculiar  advan- 
tage of  this  natural  condition  of  soil  may  be  largely 
met  where  it  is  possible  to  secure  an  abundance  of 
water  and  plant -food  in  soluble  forms.  In  the  ab- 
sence of  an  abundance  of  water,  even  the  best  judg- 
ment in  application  of  fertilizers  will  not  result  in 
satisfactory  growth.  A  heavy  application  of  the  basic 
mixture  (p.  267)  —  a  ton  per  acre,  used  at  time  of  set- 
ting the  plants — may  be  followed  with  advantage  by 
frequent  and  reasonably  heavy  top -dressings  of  nitrate 
of  soda,  100  pounds  per  acre  or  more,  and  well  worked 
into  the  soil.  This  abundance  of  soluble  nitrogen  will 
contribute  toward  that  rapidity  of  growth  which  is 
accompanied  by  the  peculiar  crispness  and  sweetness 
that  gives  edible  quality  to  this  vegetable.  In  the 
absence  of  sufficient  water  and  food,  not  only  is  the 
growth  of  the  plant  retarded,  but  the  quality  of  that 
obtained  is  materially  influenced,  since  the  develop- 
ment of  the  bitter  flavor  and  fibrous  character  that 
frequently  cause  a  reduced  consumption  of  this  valu- 
able plant  is  apparently  encouraged. 

What  has  already  been  said  concerning  this  vege- 
table is  true  of  a  number  of  others  :    the  main  thing 


276  FEBTILIZER8 

is  to  see  to  it  that  such  an  abundance  of  available 
food  of  the  right  kind  is  provided  as  to  make 
possible  a  rapid  growth  when  other  conditions  are 
favorable.  This  is  one  of  the  primary  necessities,  if 
a  high  yield  of  good  quality  product  is  obtained. 

SWEET    CORN 

In  the  ease  of  sweet  corn,  the  early  crop  is  usu- 
ally the  most  profitable.  The  recommendations  that 
are  made  for  the  fertilization  of  the  field  crop  do  not 
apply  to  this,  because  the  object  is  not  the  matured 
crop,  which  makes  its  greatest  development  in  July 
and  August,  the  most  favorable  season  of  growth, 
but  the  early  green  product,  which  is  often  harvested 
before  the  field  crop  has  fairly  begun  to  grow.  This 
early  and  rapid  growth,  therefore,  cannot  be  attained 
by  methods  of  fertilization  suitable  for  the  field  crop 
(Chapters  X  and  XII).  It  can  be  accomplished  only 
when  an  abundance  of  the  mineral  foods  is  present, 
and  when  the  nitrogen  is  in  part,  at  least,  in  forms 
which  may  be  directly  absorbed,  as  much  growth  must 
be  made  previous  to  the  time  that  nitrification  takes 
place  in  the  soil. 

The  large  quantity  of  well -rotted  manure  which, 
until  recently,  was  practically  the  only  manure  used 
for  this  crop,  while  extremely  valuable,  can  be  in  part 
substituted  by  a  liberal  dressing  of  the  minerals, 
phosphoric  acid  and  potash,  and  further  supplemented 
by  nitrogen  in  readily  available  forms.  The  use  of 
the  basic  formula  (p.  267),  reenforced  by  an  applica- 


NITRATES  FOB   SPINACH  AND   LETTUCE        277 

tion  of  nitrogenous  materials,  partly  in  the  form  of 
nitrate,  and  partly  in  quickly  available  organic  forms, 
as  blood,  cotton -seed  meal,  or  tankage,  may  be  prac- 
ticed with  advantage. 

EGG-PLANT,     SPINACH,     LETTUCE    AND    RHUBARB 

The  egg-plant  belongs  to  the  same  botanical  family 
as  the  potato,  and  while  specifically  benefited  by  the 
fertilizers  recommended  for  that  crop,  is  improved 
by  the  further  addition  of  nitrogen,  which  stimulates 
an  early  leaf  growth.  Good  organic  forms  are  quite 
as  useful  as  the  nitrates  or  ammonia,  unless  the  latter 
are  used  frequently  as  top -dressings. 

Spinach  and  lettuce,  grown  for  their  tops  or  the 
edible  portion  of  the  leaf,  are  encouraged  in  their 
development  by  an  abundance  of  available  nitrogen, 
as  this  element  is  the  one  which  contributes  more 
than  any  other  to  formation  of  leaf.  Abundant  growth 
of  the  right  sort  is  only  accomplished  when  it  is  pres- 
ent in  such  quantities  and  in  such  forms  as  to  con- 
tinuously supply  the  plant  with  its  needs.  Reasonably 
heavy  dressings  of  the  basic  formula  (p.  267),  1,000 
pounds  per  acre,  or  over,  at  time  of  planting,  should 
be  followed  by  a  top-dressing  of  100  pounds  per 
acre  of  nitrate  after  the  plants  are  well  started.  The 
late  fall  and  winter  growth  of  the  spinach  is  espe- 
cially benefited  by  the  application  of  nitrates. 

Rhubarb  is  a  crop  somewhat  similar  to  asparagus, 
in  that  it  is  a  perennial,  and  that  the  best  fertilization 
is  one  which  not  only  provides  food  for  the  growth  of 


278  FERTILIZERS 

the  immediate  crop,  but  which  encourages  the  growth 
of  top  after  the  regular  crop  is  harvested,  and  thus 
restores  the  vitality  of  the  plant, — which  has  been 
weakened  by  the  continuous  removal  of  the  stalk  and 
leaf, — and  enables  it  to  store  up  energy  for  the  sub- 
sequent crop.  An  annual  application  of  1,500  pounds 
of  the  basic  formula  (p.  267)  early  in  the  spring, 
preferably  plowed  in,  may  be  followed  with  advantage 
by  a  top-dressing  of  150  pounds  per  acre  of  nitrate 
of  soda  in  about  two  weeks  after  harvesting  has  be- 
gun, and  a  similar  dressing  after  hars^esting  has 
ceased.  These  dressings  should  be  cultivated  into  the 
soil,  unless  immediately  followed  by  rain,  which  will 
distribute  the  salt  into  the  lower  layers  of  soil.  Plants 
of  this  sort,  from  which  only  one  crop  can  be  secured, 
should  be  stimulated  to  the  largest  possible  production. 

ONIONS,    ONION   SETS   AND   SCALLIONS 

The  growing  of  onions,  either  from  seed  or  from 
sets,  and  the  growing  of  sets  according  to  "intensive" 
systems  of  practice,  requires  a  soil  of  a  suitable  physical 
character,  and  also  that  it  shall  be  well  supplied  with 
all  of  the  essential  constituents  of  fertility.  The 
minerals  should  be  supplied  in  abundance  by  super- 
phosphates and  potash  salts,  while  the  nitrogen  should 
be  supplied  in  the  most  active  forms,  and  in  even 
larger  amounts  than  for  many  other  crops.  The 
present  systems  of  growing  these  crops  require  that 
the  sets  shall  be  planted  and  the  seed  sown  more 
thickly   than    was   formerly   believed    to  be   desirable. 


FERTILIZERS   PREFERABLE    TO   MANURE       279 

which  permits  of  a  larger  yield  per  unit  of  area, 
though  it  requires  better  culture  and  a  very  much 
larger  quantity  of  available  plant -food  than  was  the 
case  under  the  former  rather  "  extensive  "  systems  of 
culture.  Except  in  the  case  of  very  early  onion  crops, 
immediate  rapid  growth  after  setting  is  not  so  essential 
as  in  the  case  of  many  other  market -garden  crops,  and 
in  the  growing  of  onion  sets,  when  the  soil  is  richly 
provided  with  food,  great  care  in  management  is 
necessary  in  order  to  secure  a  development  of  bulb 
that  shall  not  be  too  large,  in  which  case  the  salable 
quality  of  sets  will  be  reduced.  Hence,  to  avoid  this, 
the  seed  should  be  spread  thickly,  in  rows  about 
3  inches  wide,  and  the  cultivable  portion  between  the 
rows  about  8  inches  wide.  With  so  large  a  portion  of 
the  surface  area  occupied  with  the  crop,  the  danger  of 
too  large  development  from  heavy  fertilization  is  greatly 
reduced. 

In  growing  scallions,  the  soil  should  not  only  be 
richly  provided  with  minerals  and  organic  forms  of 
nitrogen,  as  in  the  case  of  the  other,  but  should  be 
supplied  early  with  soluble  nitrate,  in  order  to  meet 
the  demands  for  this  element  before  it  is  available  from 
soil  sources.  In  the  growing  of  crops  which  require  so 
much  hand  labor  as  onions,  fertilizers  are  also  pref- 
erable to  yard  manures,  because  they  are  free  from 
weed  seed.  Further,  fertilizers  do  not  contribute 
toward  the  development  of  insects  or  diseases,  as  is 
sometimes  the  case  with  manures,  particularly  with  the 
product  derived  from  city  stables. 

A  good  general  fertilizer  for  onion  sets  for  soils  of 


280  FERTILIZERS 

fair  fertility  may  consist  of  about  50  pounds  per  acre 
of  nitrogen  in  organic  forms,  as  dried  blood,  cotton- 
seed meal  or  tankage,  60  of  phosphoric  acid,  which  may 
be  partly  in  organic  forms,  as  bone  or  tankage,  and 
100  of  actual  potash,  derived  from  a  muriate.  The 
application  of  a  formula  containing — 

Nitrogen 5  % 

Phosphoric  acid 6  % 

Potash 10  % 

at  the  rate  of  1,000  pounds  per  acre,  and  well  worked 
into  the  soil  previous  to  planting,  would  furnish  these 
amounts,  and  this  application,  together  with  a  top- 
dressing  of  from  75  to  100  pounds  per  acre  of  nitrate 
of  soda,  or  60  to  75  pounds  of  sulfate  of  ammonia, 
two  or  three  times  at  intervals  of  about  three  weeks, 
the  first  after  the  crops  have  well  started,  would  pro- 
vide not  only  an  abundance  of  food  of  the  right  sort, 
but  the  nitrogen  when  needed,  without  danger  of  loss. 

If  the  soil  has  been  well  dressed  with  a  general 
fertilizer,  as  above  described,  the  scallions  should 
receive  a  dressing  of  nitrate  just  as  soon  as  growth 
begins  in  the  spring,  as  rapid  and  early  growth  at  this 
season  will,  other  conditions  being  equal,  depend  upon 
the  supply  of  available  nitrogen,  and  nitrogen  in 
available  forms  is  not  usually  present  in  the  soil  in 
sufficient  quantities  so  early  in  the  season. 

In  all  of  the  suggestions  made  as  to  the  fertilization 
of  market -garden  crops,  not  only  has  the  question  of 
yield  been  kept  in  mind,  but  also  the  quality  of   the 


FERTILIZERS    VS.    MANURES  281 

product,  which  is  a  measure  of  salability.  The  ques- 
tion is  often  raised  as  to  whether  the  forcing  of  these 
crops  by  means  of  active  fertilizers  may  not  result  in 
too  coarse  and  one-sided  a  growth.  Such  growth  does 
frequently  follow  a  heavy  fertilization  with  nitrogen, 
if  accompanied  by  too  light  a  fertilization  with  min- 
erals. The  tendency  of  the  plant  is  to  make  a  normal 
development  when  a  sufficiency  of  all  of  the  fertility 
elements  are  present,  but  in  these  crops  the  object  is 
really  a  one-sided  growth  in  many  cases,  since  that 
growth  is  usually  better  adapted  for  the  purpose  than 
that  obtained  under  what  may  be  regarded  as  normal 
conditions.  It  must  be  remembered,  too,  in  the  grow- 
ing of  certain  vegetables,  such  as  radishes,  celery,  etc., 
or  those  in  which  the  roots  are  the  edible  portion,  that 
commercial  fertilizers  do  not  contribute  any  undesirable 
flavors.  In  fact,  they  are  often  largely  responsible 
for  those  peculiar  characteristics  which  give  quality; 
whereas,  when  these  vegetables  are  grown  by  the  ex- 
clusive and  necessarily  excessive  applications, — if  large 
yields  are  to  be  secured, — of  natural  manures,  unde- 
sirable qualities  are  frequently  contributed  by  them. 


CHAPTER  XIV 

ORCHARD  FRUITS  AND  BERRIES 

It  is  not  until  within  recent  years  that  the  question 
of  manuring  or  fertilizing  fruit  trees  and  berries  has 
come  to  be  of  particular  interest.  This  is  due  primarily 
to  the  fact  that  demands  for  fruit  and  berries  have 
been  relatively  limited  as  compared  with  the  staple 
crops.  Hence,  fruit-growing  as  a  business,  or  on  a 
commercial  scale,  is  comparatively  new,  though  the 
opinion  is  quite  prevalent  among  fruit-growers  that 
trees,  particularly,  are  indigenous  to  most  soils,  and 
grow  freely  like  weeds,  and  that,  therefore,  orchard 
crops  are  not  as  exhaustive  of  the  fertility  elements 
as  others.  They  cite,  as  an  argument  on  this  point, 
the  fact  that  lands  from  which  timber  has  been 
recently  removed  are  much  more  productive  than 
those  upon  which  many  regular  farm  crops  have 
been  grown.  Scientific  investigation  and  practical 
experience,  however,  teach  that  forest  growth  and 
fruit  growth  are  quite  different  in  respect  to  the 
needs  of  fertilizing  elements,  and  that  progressive 
fruit -culture  demands  that  quite  as  much  attention 
shall  be  given  to  the  matter  of  providing  proper 
plant -food  as  is  now  known  to  be  desirable  for 
the  other  and  more  common  crops  of  the  farm 
grown    for    profit. 

(282) 


THJ]    GROWTH   OF   FRUIT   CROPS  283 

•    FRUIT    CROPS    DIFFER    FROM    GENERAL    FARM    CROPS. 

It  is  obvious  that  suggestions  as  to  the  character 
of  the  fertilization  of  the  cereal  crops,  grasses  and 
vegetables,  must  be  somewhat  different  from  these 
fruits,  because  the  former  differ  from  the  latter  not 
only  in  their  habits  of  growth,  but  in  the  character 
and  composition  of  the  crop  produced,  and  in  their- 
relation  to  soil  exhaustion.  General  farm  crops,  with 
few  exceptions,  require  but  one  year  for  the  entire 
processes  of  vegetation  and  maturation.  Fruit  crops, 
as  a  rule,  require  a  preparatory  period  of  growth  of 
tree  or  bush  before  any  crop  is  produced,  which  is 
longer  or  shorter  according  to  the  kind  of  fruit. 
Furthermore,  after  the  fruit-bearing  period  begins, 
the  vegetative  processes  do  not  cease,  but  are  coinci- 
dent with  the  growth  and  ripening  of  the  fruit.  The 
crop  product,  or  the  fruit,  also  differs  materially  in 
its  character  from  the  general  farm  crop,  or  from 
vegetables,  which  reach  their  harvesting  stage  and 
die  in  one  season,  because  for  many  kinds  a  whole 
season  is  required   for   growth   and   development. 

That  is,  in  fruit-growing  it  is  necessary  that  there 
shall  be  a  constant  transfer  of  the  nutritive  juices 
from  the  tree  to  the  fruit  throughout  the  entire  grow- 
ing season,  while  the  growth  for  each  succeeding  year 
of  both  tree  and  fruit  is  dependent  upon  the  nutrition 
stored  up  in  buds  and  branches,  as  well  as  upon  that 
which  may  be  derived  directly  from  the  soil. 

"In  the  next  place,  the  relation  of  fruit-growing 
to  soil  exhaustion  is  very  different  from  that  in  gen- 


284  FERTILIZERS 

eral-crop  farming,  because  in  orchards  there  is  an 
annual  demand  for  specific  kinds  and  definite  pro- 
portions of  soil  constituents.  It  is  really  a  continu- 
ous cropping  of  the  same  kind,  and  there  is  no  oppor- 
tunity, as  in  the  case  of  ordinary  farm  crops,  to  cor- 
rect the  tendency  to  exhaustion  by  a  frequent  change 
of  crops,  or  the  frequent  growth  of  those  which  re- 
quire different  kinds  and  amounts  of  plant -food  con- 
stituents." * 

THE      SPECIFIC      FUNCTIONS      OF      THE      ESSENTIAL 
FERTILIZING      CONSTITUENTS 

It  must  be  admitted,  however,  that  the  general 
principles  of  manuring,  as  applied  to  farm  crops,  also 
apply  to  fruit  and  berry  crops ;  that  is,  the  essential 
manurial  constituents  must  be  the  same. 

"A  fruit  tree  will  not  make  normal  growth  in  a  soil 
destitute  of  nitrogen.  That  nitrogen  encourages  leaf 
growth  is  a  recognized  fact,  and  since  trees  grow  by 
means  of  both  leaf  and  root,  its  presence  is  required  in 
the  soil  in  order  to  promote  the  growth  and  extend  the 
life  of  the  tree.  It  is  very  evident,  too,  that  potash  is 
an  essential  constituent  in  the  growth  of  fruits,  not 
only  because  it  constitutes  a  large  proportion  of  the 
ash  of  the  wood  of  the  apple,  pear,  cheiry  and  plum, 
and  more  than  50  per  cent  of  the  ash  of  fruit,  but 
because  it  forms  the  base  of  the  well-known  fruit  acids. 
Phosphoric    acid   is    also   very   essential    in    order    to 


*Voorhees,  "Manuring  Orchards."    Lecture  before  Massachnsettes  Horti- 
cultural Society,  1896. 


SOILS  ADAPTED  FOB   FRUIT   CHOPS  285 

nourish  a  tree  properly,  as  well  as  to  insure  proper 
ripening,  though  it  is  apparent  from  such  investigations 
as  have  been  made  that  this  constituent  is  relatively  of 
less  importance  than  for  the  cereals. 

"It  is  also  a  matter  of  common  observation,  that  in 
the  prodnction  of  stone-fruits,  particularly,  lime  is  an 
important  constituent.  Its  functions  seem  to  be  to 
strengthen  the  stems  and  woody  portion  of  the  tree,  to 
shorten  the  period  of  growth,  and  to  hasten  the  time 
of  ripening.  Fruit  trees  growing  on  soils  rich  in  lime 
show  a  stocky,  steady,  vigorous  growth,  and  the  fruit 
ripens  well,  while  those  on  soils  which  contain  but 
little  lime,  particularly  the  clays,  appear  to  have  an 
extended  period  of  growth,  the  result  of  which  is  that 
the  wood  does  not  mature  and  the  fruit  does  not  ripen 
properly."  * 

THE  CHARACTER  OF   SOIL  AN   BIPORTANT  CONSIDERATION 

Soils  which  possess  good  mechanical  condition, 
are  rich  in  the  essential  constituents — nitrogen,  phos- 
phoric acid  and  potash — contain  a  good  propor- 
tion of  lime,  and  are  well  drained  and  cultivated,  are 
naturally  well  adapted  for  fruit  trees,  as  well  as  for 
other  crops,  and  the  exhaustion  of  such  soils  will  not 
become  apparent  for  a  long  time.  But  soils  of  this 
character  are  the  exception  rather  than  the  rule,  and 
the  growth  of  fruit  on  those  which  possess  the  opposite 
characteristics  cannot  be  continued  for  any  considerable 
period  without    an    artificial    supply   of    the    fertility 

*« Manuring  Orchards."    Massachusetts  Horticultural  Society,  1896. 


286  FERTILIZERS 

elements.  In  fact,  it  is  doubtful  whether  it  ever  pays 
to  attempt  to  grow  fruits  on  soils  of  the  latter  char- 
acter without  supplying  them  with  an  abundance  of 
the  essential  fertilizer  elements. 

In  the  matter  of  berries,  which  are  crops  especially 
well  adapted  to  soils  which  possess  a  light,  open 
character,  but  which  are  not  naturally  supplied  with 
the  essential  plant -food  constituents,  proper  manuring 
becomes  of  even  more  importance  than  for  the  tree 
fruits  ;  though,  because  of  their  shorter  period  of  life, 
one  or  two  good  crops  may  be  secured  without  heavy 
fertilization. 

On  the  whole,  however,  for  all  of  these  crops  the 
great  need  at  the  present  time  is  for  a  larger  use  of 
fertilizing  materials,  not  only  because  a  larger  yield 
may  be  obtained  thereby,  but  because  the  quality  of 
the  product  is  far  superior  to  that  grown  under  con- 
ditions which  are  not  perfect  in  this  respect.  Quality, 
which  is  determined  by  size  and  appearance,  is,  other 
things  being  equal,  largely  dependent  upon  an  abun- 
dant supply  of  plant-food.  It  is  manifestly  impos- 
sible to  include  all  fruit  and  berry  crops  in  one  general 
group,  though  possessing  points  of  resemblance,  be- 
cause the  different  ones  vary  more  or  less  in  their 
character.  The  trees  of  certain  of  them  are  long-lived 
— 40  years  or  more, — while  others  are  comjjaratively 
short-lived — 10  years  or  less.  In  certain  of  them  the 
cropping  period  is  short;  the  fruit  ripens  at  once,  while 
in  others  the  ripening  period  extends  over  a  consid- 
erable time.  They  also  differ  in  reference  to  their 
demands  for  plant -food,  certain  of  them  requiring  an 


NJ!:CESSITr  FOB   CONTINUOUS  FEEDING        287 

abundance  of  available  food,  while  others  can  readily 
absorb  the  food  necessary  for  their  growth  from  rela- 
tively  insoluble  compounds.  In  the  discussion,  similar 
recommendations  may  be  made  in  many  cases,  though  it 
is  desirable  that  each  class  of  fruits  shall  be  considered 
separately,  and  also  that  distinctions  should  be  made 
between  what  are  regarded  as  good  soils,  as  medium 
soils  and  as  poor  soils,  in  respect  to  their  content  of 
plant -food. 

THE    GENERAL    CHARACTER    OF    THE    FERTILIZATION 

It  must  be  borne  in  mind,  also,  that  inasmuch  as 
the  fruit  crop  is  not  derived  from  annual  plants,  but 
from  perennials,  the  character  of  the  feeding  may  be 
very  different  from  that  in  which  the  entire  plant 
serves  as  a  crop,  as  is  the  case  with  the  cereals  and 
most  vegetables.  Hence,  the  fertilizers  applied  need 
not  all  be  of  such  a  character  as  to  be  immediately 
available.  That  is,  the  fertilizing  materials  may  be 
such  as  to  provide  for  a  gradual  and  continuous  feed- 
ing. Those  forms  which  decay  relatively  slowly  are, 
perhaps,  quite  as  good,  if  not  better,  for  many  kinds 
of  fruits  than  those  which  by  virtue  of  their  solubility 
and  immediate  availability  are  more  stimulative  in 
their  character.  Those  fertilizers  which  do  not  con- 
tribute to  the  immediate  feeding  of  the  tree  or  plant, 
but  rather  add  to  the  reserves  of  potential  plant -food 
in  the  soil,  should,  however,  in  many  cases  be  sup- 
plemented by  those  which  act  more  quickly,  in  order 
to   supply   an   abundance   of   available  food  at  special 


288  FERTILIZERS 

times  and  seasons.  In  general,  therefore,  a  basic 
formula,  the  chief  claim  of  which  is  that  it  fui-nishes 
large  percentages  rather  than  specific  proportions  or 
forms  of  plant -food,  may  be  more  reasonably  adopted 
for  fruits  and  berries  than  for  other  crops,  because 
it  may  be  applied  with  advantage  to  all  of  the  fruits, 
the  amounts  to  be  applied  to  be  adjusted  to  meet  the 
requirements  of  the  different  kinds  of  crop  and  the 
different  kinds  of  soil.  Fertilizers  which  have  been 
found  to  be  very  serviceable  for  fruit  crops  have 
been  made  according  to  the  following  formulas,  the 
materials  of  which  are  familiar  to  all,  and  may  be 
readily  obtained  from  dealers  :  (1)  One  part,  or  100 
pounds  each,  of  ground  bone,  acid  phosphate  and  mu- 
riate of  potash;  or  (2),  a  mixture  of  one  and  one -half 
parts,  or  150  pounds,  of  ground  bone,  and  one  part, 
or  100  pounds,  of  muriate  of  potash;  the  mixture  of 
either  to  be  applied  in  all  cases.  For  fruit  trees  on 
soils  of  good  natural  character,  further  additions  of 
more  active  forms  of  the  various  constituents  may 
not  be  needed,  while  on  light  soils,  or  those  of  a  me- 
dium character,  or  for  berries,  they  should  be  added. 

The  chief  point  to  observe  is  that  an  excess  of 
nitrogen  must  be  avoided,  and  that  if  this  element  is 
applied  in  active  forms  it  should  be  used  at  such 
times  as  to  enable  the  plant  to  appropriate  it  early 
in  the  season,  and  thus  become  assimilated  before 
the  beginning  of  winter,  the  danger  from  too  great 
an  excess  of  nitrogenous  fertilizers  being  that  it 
causes  a  too  rapid  growth  of  both  wood  and  fruit, 
which  do  not  ripen  well. 


METHOD   OF  APPLICATION  IMPORTANT         289 
THE    APPLICATION    OF    FERTILIZERS    FOR    FRUITS 

A  point  which  should  be  carefully  observed  in 
the  fertilizing  of  orchards  is  the  method  of  applica- 
tion. The  fertilizers  should,  as  far  as  possible,  be  dis- 
tributed throughout  the  lower  layers  of  soil,  where  the 
feeding  roots  are  located.  If  applied  wholly  on  the 
surface  of  the  soil,  the  tendency  of  the  root  is  to  go 
to  that  point,  or  where  the  food  is,  and  trees  which 
have  the  larger  proportion  of  the  feeding  roots  near 
the  surface  are  more  liable  to  suffer  from  drought 
than  those  which  have  them  distributed  at  greater 
depths  in  the  soil.  Hence,  in  the  application  of  fer- 
tilizers to  orchards,  particularly  in  the  early  life  of 
the  trees,  they  should,  as  far  as  possible,  be  well 
worked  into  the  soil,  which  may  be  readily  accom- 
plished by  applying  upon  the  surface  before  plowing. 
The  after -fertilization,  if  it  seems  desirable  to  leave 
the  orchard  in  sod,  may  be  upon  the  surface,  though 
in  that  case  the  soluble  fertilizers  are  preferable, 
since  they  would  rapidly  descend,  while  the  insoluble 
would  do  so  more  slowly,  or  only  as  rapidly  as  they 
became   soluble. 

THE    FERTILIZATION    OF    APPLES    AND    PEARS 

The  necessity  for  the  application  of  fertilizers  in 
the  growing  of  apples  and  pears  is  largely  due  to 
the  fact  that  it  is  really  a  continuous  cropping  of  the 
same  kind,  and,  therefore,  more  exhaustive  than  a 
cropping  which  removes  more  plant -food   in  the  same 


290  FERTILIZERS 

period  of  time.  While  upon  good  soils  the  trees  may 
be  able  to  acquire  sufficient  food  to  mature  maximum 
crops  for  a  considerable  period,  the  life  of  the  tree, 
as  well  as  the  character  of  the  fruitage,  will  be  very 
favorably  influenced  by  the  fertilization. 

An  experiment*  bearing  upon  this  point  is  very 
instructive,  as  indicating  the  need  of  manures  for 
fruit  trees,  not  only  in  reference  to  the  amount 
removed,  but  also  in  reference  to  the  proportions  of 
the  essential  constituents  required.  This  study  shows 
that  the  plant -food  contained  in  20  crops  of  apples, 
of  15  bushels  per  tree,  and  35  trees  per  acre,  and  in 
the  leaves  for  the  same  period,  amounts,  in  round 
numbers,  to  1,337  pounds  of  nitrogen,  310  of  phos- 
phoric acid,  and  1,895  of  potash.  These  amounts  of 
plant -food  are  compared  with  the  amounts  that  would 
be  removed  by  20  years'  continuous  cropping  with 
wheat,  assuming  an  average  yield  of  15  bushels  of 
wheat  per  acre,  and  7  pounds  of  straw  to  3  bushels 
of  grain;  viz.,  660  pounds  of  nitrogen,  211  of  phos- 
phoric acid,  and  324  of  potash.  By  this  comparison 
it  is  shown  that  the  20  crops  of  apples  remove  more 
than  twice  as  much  nitrogen,  half  as  much  again  of 
phosphoric  acid,  and  nearly  three  times  as  much  pot- 
ash as  the  20  crops  of  wheat. 

These  results  are  valuable  in  indicating  the  rate  of 
soil  exhaustion  by  apple -growing.  It  is  to  be  remem- 
bered, however,  that  the  larger  root  development  of 
the  tree  would  enable  it  to  draw  its  nourishment  from 


*  Cornell   Exp.  Sta.,  Bulletin  No.  103,  "SoD  Depletion  in  Respect  to  the 
Care  of  Fruit  Trees." 


THE  NEED   OF  FERTILIZERS  291 

a  larger  area  of  soil  than  is  the  case  with  wheat,  and 
thus  probably  permit  of  normal  growth  for  a  longer 
period. 

Too  many  are  satisfied  with  short  crops  of  medium 
fruit,  with  off-years  and  with  short-lived  trees,  largely 
because  they  do  not  know  that  all  of  these  conditions 
may  be  improved  by  a  proper  feeding  of  the  tree,  and 
that  such  feeding  will  usually  result  in  a  very  largely 
increased  profit. 

Statistics  gathered  in  the  state  of  New  Jersey*  show 
that  over  90  per  cent  of  the  commercial  apple -growers 
in  the  southern  and  central  sections  use  fertilizers  or 
manures  for  their  orchards,  whereas,  in  the  northern 
section  about  70  per  cent  use  manures.  In  the  northern 
section  the  orchards  are  usually  located  upon  soils  of  a 
very  high  natural  strength,  and  which  are  peculiarly 
well  adapted  for  the  growing  of  fruits,  while  in  the 
central  and  southern  sections,  the  soils  in  many  sections 
are  of  medium,  if  not  of  very  low  fertility.  Hence, 
while  the  larger  proportion  of  the  growers  use  fertili- 
zers or  manures  upon  the  poor  soils,  a  very  considerable 
number  use  manures  for  orchards  located  upon  soils 
which  are  regarded  as  of  the  best;  yet  all  claim  that  it 
is  a  paying  practice. 

There  is  also  a  difference  in  the  time  at  which 
manuring  or  fertilizing  should  begin.  When  the  soil 
is  naturally  good  the  fertilization  need  not  begin  with 
the  setting  of  the  tree,  as  the  food  obtainable  is  usually 
sufficient   to  provide  for  a  good   growth  of    leaf   and 


♦Bulletin  No.  119,  New  Jersey  Experiment  Station, 


292  FERTILIZERS 

wood,  and  in  many  cases  maximum  crops  of  fruit  for  a 
number  of  years,  though  even  here  fertilization  should 
preferably  begin  as  soon  as  large  crops  are  produced, 
whereas,  on  the  lighter  soils,  fertilization  should 
begin  when  the  tree  is  set. 

The  Amounts  to  he  Applied 

For  these  crops,  either  of  the  basic  mixtures  sug- 
gested (p.  288)  will  provide  a  sufficient  proportion  of 
nitrogen,  except  possibly  upon  the  more  sandy  soil. 
On  light  soils,  the  necessity  for  liberal  fertilization  with 
nitrogen  is  frequently  apparent,  in  which  case  it  may 
be  applied  in  organic  forms,  preferably  from  materials 
that  do  not  decay  too  rapidly,  as  tankage,  or  wool  waste, 
and  other  waste  nitrogenous  materials,  because  they  may 
be  obtained  more  cheaph%  and  because  they  furnish  the 
nitrogen  quite  as  rapidly  as  is  needed  by  the  tree.  In 
many  cases  it  is  possible  to  obtain  the  necessary  nitro- 
gen from  the  growing  of  leguminous  crops,  as  crimson 
clover,  though  when  these  are  used  they  should  be 
plowed  down  early  in  the  spring,  in  order  that  their 
growth  may  not  interfere  with  the  growth  of  the  tree. 
If  they  are  allowed  to  remain  until  mature,  they  ab- 
sorb not  only  the  food  that  may  be  necessary  for  the 
growth  of  tree  and  fruit,  but  the  moisture  also,  and 
thus  they  frequently  injure  rather  than  improve  the 
crop  prospects. 

On  soils  of  good  natural  character,  the  fertilization 
of  apples  and  pears  should  begin  as  soon  as  the  trees 
reach  the  bearing  period,  and  an  annual  application  of 


ABUNDANCE   OF  MINERALS  NECESSARY       293 

400  pounds  per  acre  of  either  formula  1  or  2  should 
be  made,  preferably  in  early  spring,  and  plowed  in. 
As  they  grow  older  and  the  yield  of  fruit  is  larger,  the 
amounts  should  be  increased.  "While  no  definite  rules 
can  be  laid  down  as  to  the  most  profitable  amounts  to 
apply,  the  best  growers  find  that  it  pays  to  use  from 
1,000  to  1,500  pounds  annually  of  mixtures  which 
furnish  practically  the  amounts  and  kinds  of  plant- 
food  contained  in  the  formulas  suggested.  The  profit 
is  found,  not  only  in  the  larger  yield,  but  in  the 
quality  of  the  fruit  and  in  the  increased  tendency 
toward  continuous  crops,  and  in  longer  life  of  the 
tree.  On  soils  of  medium  character  the  fertilization 
should  begin  earlier,  and  the  amounts  of  the  basic 
fertilizer  should  be  larger.  In  many  cases,  too,  nitro- 
gen, in  addition  to  that  contained  in  the  basic  formula, 
should  be  added,  the  kind  and  form  depending,  per- 
haps, upon  the  relative  cost  more  than  upon  any  other 
one  thing,  the  minimum  amount  to  be  20  pounds  per 
acre,  or  an  equivalent  of  125  pounds  of  nitrate  of 
soda. 

On  poor  soils,  the  necessity  for  fertilization  is  nat- 
urally greater  than  for  either  of  the  others.  In  fact, 
on  these  liberal  fertilization  —  500  pounds  per  acre  of 
basic  formula  No.  2 — should  precede  the  setting  of  the 
trees,  and  be  continued  annually.  On  these  soils,  too, 
green  manuring  as  a  source  of  nitrogen  can  be  prac- 
ticed with  safety  for  a  longer  period  than  in  the  pre- 
ceding case.  In  the  presence  of  an  abundance  of 
minerals,  the  need  for  nitrogen  is  indicated  by  the 
color  of  the  foliage.     If  it  lacks  vigor  and  is  yellow  in 


294  FERTILIZERS  \ 

the  spring,  rather  than   green,  a  dressing  of  from  100  \ 

to  150  pounds  of  nitrate  of  soda  will  supply  the  needs  ; 

to  better  advantage  than  any  other  form.  \ 


PEACHES 

Peaches  diJSfer  from  apples  and  pears  in  respect  to 
fertilization,  because  the  period  of  development  of 
the  tree,  preparatory  to  bearing,  is  shorter,  and  be- 
cause the  cropping  is  usually  much  more  exhaustive. 
Hence,  the  demands  for  added  plant -food  are  propor- 
tionately greater  in  the  early  life  of  the  tree,  and  are 
different,  because  of  their  more  rapid  growth.  That 
is,  forms  of  nitrogen  that  are  more  available  are  pre- 
ferred to  the  slowly  available  materials  recommended 
for  apples  and  pears. 

The  Need  of  Fertilizers 

The  results  of  an  experiment  conducted  by  the 
New  Jersey  Experiment  Station*  are  interesting  and 
valuable,  as  bearing  upon  this  point.  They  show  the 
value  of  fertilization,  not  only  in  increasing  the  yield 
of  crops,  but  in  extending  the  period  of  life  of  the 
trees,  and  in  overcoming  unfavorable  crop  conditions. 
The  soil  upon  which  the  experiment  was  conducted 
possessed  only  medium  fertility,  good  mechanical  con- 
dition, and  was  fairly  representative  of  soils  naturally 
well  adapted  for  peach -growing.  The  fertilized  plots 
received  annually — 


•Annual  Reports  of  New  Jersey  Experiment  Station,  1884-94. 


THE  NEW  JERSEY  EXPERIMENTS  295 

Nitrate  of  soda 150  lbs. 

Bone-black  superphosphate 350    " 

Muriate  of  potash 150    " 

per  acre,   whereas  the  manured  plot   received  manure 
at  the  rate  of  20  tons  per  acre. 

The  following  tabular  statement  shows  the  results 
obtained : 

I.    The  Yield  "without  Manure 

Baskets 
per  acre 

1884-1891,  inclusive,    8  years,  average  per  year 65.7 

1884-1895,         "  10      "  "  "  60.3 

1887-1891,    "    (5  crop  years),  average  per  year  .  .  .105.0 

1887-1893,    "     7  I.    <«      a  a  gg^ 

II.    The  Yield  with  Complete  Chemical  Manure 

Baskets 
per  acre 

1884-1891,  inclusive,    8  years,  average  per  year 164.2 

1884-1893,         "  10      "  "  " 183.4 

1887-1891,         "  (5  crop  years),  average  per  year     .    .    .262.8 

1887-1893,         "  7     <«         <i  «<  a  262.0 

III.    The   Yield  with  Barnyard  Manure 

Baskets 
per  acre 

1884-1891,  inclusive,    8  years,  average  per  year 169.5 

1884-1893,         "  10      "  "  "  194.7 

1887-1891,         "  (5  crop  years) ,  average  per  year     .    .    .271.3 

1887-1893,         "  7     <<         «i  u  ««  _  276.8 

IV.    The   Relative  Yield   in  an  Unfavorable   Season 

Baskets 
per  acre 

1889,  unmanurod 10.9 

1889,  fertilized 152.5 

1889,  manured 162.5 


296  FERTILIZERS 

"The  first  point  of  importance  and  value  observed 
is  in  reference  to  the  number  of  crops  that  were 
secured.  On  the  unmanured  land,  the  crops  secured 
after  eight  years  were  so  small  as  to  materially  reduce 
the  average  for  the  whole  period,  while  for  the  ma- 
nured land  the  average  for  the  whole  period  was  not 
only  not  reduced,  but  very  materially  increased ;  that 
is,  the  crops  secured  on  these  after  the  trees  on  the 
unmanured  land  had  practically  ceased  to  bear  were 
greater  proportionately  than  those  secured  previous 
to  that  time.  This  was  true  both  for  the  fertilized 
and  manured  land. 

"In  the  next  place,  it  is  shown  that  the  yield  was 
very  materially  increased  by  the  use  of  manures, 
either  in  the  form  of  artificial  or  natural  supplies, 
and  the  differences  in  yield  derived  from  these  two 
forms  are  very  slight,  indicating  that  very  much 
smaller  amounts  of  actual  plant -food  in  quick -acting 
forms  were  quite  as  useful  as  larger  amounts  of  the 
less  available  forms  in  which  the  food  exists  in 
natural   manure   products. 

"For  the  ten  years,  the  fertilized  plot  received  250 
pounds  of  nitrogen,  560  of  phosphoric  acid  and  750  of 
potash,  while  the  yard  manure  plot  received  —  assum- 
ing the  average  composition  of  yard  manure  —  2,000 
pounds  of  nitrogen,  2,000  of  phosphoric  acid  and 
1,600  of  potash;  yet  with  eight  times  as  much 
nitrogen,  nearly  four  times  as  much  phosphoric  acid 
and  more  than  twice  as  much  potash,  the  yield  was 
but  113  baskets  greater,  or  an  average  of  11  baskets 
per   acre. 


FERTILIZERS  FOR   GOOD  AND   POOR   SOILS     297 

"In  the  third  place,  it  is  interesting  to  observe — 
and  it  is  a  point  of  great  importance — the  effect  of 
an  abundance  of  food  in  overcoming  unfavorable 
weather  or  seasonal  conditions.  The  year  1889  was 
extremely  unfavorable,  and  the  crop  throughout  the 
state  was  small.  In  this  experiment  the  unmanured 
plot  yielded  at  the  rate  of  10.9  baskets  per  acre, 
while  the  manured  and  fertilized  plots  both  showed  a 
yield  exceeding  150  baskets  per  acre.  The  manure 
strengthened  and  stimulated  the  trees,  and  enabled 
them  to  successfully  resist  such  conditions  as  were 
fatal   to   the   crop   on   the   unmanured    land. 

"This  point  is  one  that  is  seldom  considered  in 
calculating  the  advantages  to  be  derived  from  proper 
manuring,  though  it  is  of  extreme  value,  since  the 
expenses  of  cultivation,  trimming,  and  interest  on 
investment  are  quite  as  great  in  one  case  as  in 
the    other."* 

t 

Methods   of  Fertilization 

On  soils  of  good  natural  character,  the  necessity 
for  fertilizing  peaches  is  seldom  apparent  until  after 
the  first  or  second  year  of  growth.  That  is,  good 
soils  will  provide  sufficient  food  for  a  normal  develop- 
ment of  leaf  and  wood,  and  any  additional  fer- 
tilization would  have  the  tendency  to  unduly  increase 
the  tree  growth.  On  medium  and  poor  soils,  the 
setting   of   the    trees    should    be    preceded    by    a   fer- 


*"  Manuring  Orchards."    Massachasetts  Horticultural  Society,  1896. 


298  FERTILIZERS 

tilization  with  one  or  the  other  of  the  basic  mix- 
tures (p.  288),  on  the  better  soils  No.  2,  and  on  the 
poorer  No.  1,  at  the  rate  of  400  to  600  pounds  per 
acre,  which  should  be  followed  by  the  application  of 
the  more  soluble  fertilizers  immediately  the  trees  begin 
to  bear.  The  need  of  nitrogen  is  often  very  marked, 
and  is  shown  by  a  lack  of  vigor  of  the  tree.  The 
soluble  nitrates  have  proved  very  valuable  as  a  source 
of  this  element,  since  from  these  the  nitrogen  may 
be  appropriated  by  the  roots  during  the  early  season, 
and  which,  if  a  sufficient  abundance  of  the  minerals 
is  present,  enables  a  normal  development  of  leaf  and 
branch.  If  the  quick -acting  nitrogenous  fertilizers 
are  applied  late,  or  if  too  large  applications  of  the 
slower -acting  nitrogenous  materials  are  applied  early, 
the  tendency  is  to  provide  for  a  continuous  feeding 
on  nitrogen,  and  thus  encourage  an  undue  develop- 
ment of  leaf  and  branch,  which  does  not  permit  the 
ripening  of  the  wood  before  the  beginning  of  winter. 
Thus  on  these  soils,  in  addition  to  an  annual  applica- 
tion of  the  basic  formula,  from  100  to  150  pounds  of 
nitrate  of  soda,  200  pounds  of  acid  phosphate  and 
100  of  muriate  of  potash  should  be  applied  early  in 
the  season  and  carefully  worked  into  the  soil. 

For  peach  crops,  too,  green  manuring  with  legumi- 
nous crops  should  be  carefully  carried  out,  since 
if  too  much  nitrogen  is  added  by  this  means,  an 
abnormal  growth  of  wood  is  encouraged,  and  a  late 
ripening  of  the  fruit  occurs ;  and  injury  to  the  tree 
may  follow  if  the  manuring  crop  is  not  used  at  the 
proper  time,  as  already  indicated. 


CAREFUL   USE   OF  NITROGEN  299 

Many  orchardists  use  much  larger  amounts  of  fer- 
tilizer than  is  here  recommended,  though  if  the  sug- 
gestions concerning  the  method  of  use  are  carried  out, 
the  quantities  named  will  be  found  sufficient  to  supply 
all   the  needs  of   maximum  crops. 

PLUMS,    CHERRIES    AND    APRICOTS 

The  fertilization  of  these  fruits,  when  grown  on 
the  different  classes  of  soils,  need  not  differ  materially 
from  that  recommended  for  peaches  under  the  same 
conditions,  though  cherries,  particularly,  require  in 
addition  to  the  essential  constituents,  nitrogen,  phos- 
phoric acid  and  potash,  a  relatively  greater  supply 
of  lime,  and  this  substance  should  be  applied  in 
addition  to  the  regular  fertilization.  Care  should 
also  be  exercised  in  the  application  of  nitrogen,  in 
order  to  prevent  a  too  great  development  of  leaf  and 
branch.  Unless  these  trees  show  a  decided  need  for 
nitrogen,  a  medium  application  of  the  second  basic 
formula  (p.  288)  will  furnish  sufficient  for  their  needs. 

CITROUS   FRUITS 

These  products — the  oranges,  lemons,  and  the  like — 
belong  to  a  distinct  class  of  fruits,  and  the  experience 
already  gained  in  their  fertilization  is  such  as  to  make 
applicable  the  suggestions  concerning  peaches,  plums 
and  apricots.  On  the  lighter  sandy  soils  of  Florida, 
which  are^ naturally  well  adapted  for  oranges,  growers 
have  found  potash  to  be  a  specially  important  element 


300  FERTILIZERS 

in  manures.  The  nitrogen  and  phosphoric  acid  should 
be  accompanied  by  a  larger  proportion  of  potash  than 
is  recommended  for  the  stone  fruits.  Great  care  should 
be  exercised  in  the  use  of  nitrogen,  though  in  the  case 
of  these  semi-tropical  crops,  the  danger  from  immature 
growth,  as  in  the  case  of  fruits  for  the  more  northern 
climates,  is  not  so  marked. 

SMALL  FRUITS   L^J    GENERAL 

These  crops  do  not  differ  from  those  already  dis- 
cussed in  reference  to  their  needs  for  liberal  fertiliza- 
tion, yet  because  of  their  different  character  of  growth, 
the  method  of  fertilization  should  be  somewhat  dif- 
ferent. They  are,  as  a  rule,  crops  which  require  a 
shorter  preparatory  season,  and  have  a  shorter  period 
of  bearing  life.  The  strawberry,  for  example,  does 
not  advantageously  bear  more  than  two  crops  without 
re -setting,  whereas  the  blackberry  and  raspberry  may 
range  in  life  from  four  to  eight  years,  and  the  goose- 
berry and  currant  are  relatively  long-lived,  provided 
they  are  supplied  with  an  abundance  of  food.  In 
respect  to  their  general  character,  they  correspond  more 
nearly  with  the  vegetable  crops  than  with  the  cereal 
grains,  in  that  they  possess  a  relatively  higher  market 
value  and  a  lower  fertility  value  than  these,  and  the 
period  of  growth  and  development  of  the  fruit  is  much 
shorter.  Therefore,  natural  sources  of  plant -food  may 
be  largely  ignored  in  their  growth,  and  the  more  quickly 
available  —  particularly  nitrogenous  and  phosphatic  — 
materials  supplied. 


A  VAILABLE  PLANT-FOOD  BEGOMMENDED       301 
STRAWBERRIES 

In  the  case  of  the  strawberry,  the  preparatory- 
period  of  growth  of  the  plant  before  bearing  is  but  one 
year,  and  the  crop  that  may  be  obtained  is  largely 
dependent  upon  the  strength  and  vigor  of  plant  which 
has  been  acquired  during  this  period.  Hence,  it  is 
desirable  that  the  soil  in  which  the  plants  are  set  should 
be  abundantl}'  provided  with  the  mineral  elements, 
particularly  with  soluble  and  available  phosphoric  acid; 
hence  an  application  of  from  500  to  800  pounds  per  acre 
of  basic  formula  No.  1  (p.  288)  is  recommended.  The 
nitrogen  should  also  be  in  quickly  available  forms,  and 
should  be  supplied  in  sufficient  quantities  at  time  of 
setting  the  plant  to  enable  it  to  mature,  and  thus  to 
withstand  the  rigors  of  winter.  Hence,  an  additional 
application  of  100  pounds  of  dried  blood,  or  its  equiva- 
lent in  nitrate  of  soda  or  ammonia,  is  advisable,  par- 
ticularly on  soils  not  previously  well  enriched  with 
organic  nitrogenous  matter.  In  the  spring  of  the  sea- 
son during  which  the  first  crop  is  harvested,  an  appli- 
cation of  a  quick -acting  fertilizer  rich  in  nitrogen  is 
desirable,  since  it  not  only  provides  for  an  early  and 
strong  growth  of  plant,  but  a  better  setting  of  fruit,  if 
other  conditions  are  favorable  ;  and  frequently,  with  a 
full  setting,  top -dressings  with  nitrate  of  soda  are 
useful,  in  order  to  insure  the  full  development  of  the 
crop.  Many  growers,  therefore,  who  have  supplied  the 
soil  liberally  with  minerals  and  nitrogen,  both  at  time 
of  setting  the  plants  and  in  the  following  spring,  make 
top -dressings  of  nitrate  of  soda  (about  100  pounds  per 


302  FERTILIZERS 

acre),  preferably  after  the  plant  has  blossomed,  in 
order  to  insure  a  sujQ&ciency  of  this  element.  This 
should  be  applied  at  this  time  rather  than  later  in  the 
season,  since  later  applications  have  a  tendency  to 
cause  a  soft  growth  of  fruit,  and  thus  injure  shipping 
qualities. 

RASPBERRIES    AND    BLACKBERRIES 

Raspberries  and  blackberries  also  require  a  soil 
well  enriched  with  the  mineral  elements,  which  insure 
an  abundant  and  strong  growth  of  canes.  The  need 
for  nitrogen,  while  apparent,  is  less  marked  than  in 
the  case  of  the  strawberries,  and  the  slower -acting 
forms  serve  a  good  purpose,  provided  they  are  not 
applied  in  too  great  quantities,  so  as  to  encourage  a  late 
growth  of  plant,  which  does  not  fully  mature.  The 
main  object  is  to  obtain  strong,  well -ripened  canes, 
and  this  can  be  accomplished  with  the  slowly  avail- 
able nitrogenous  substances,  provided  an  abundance 
of  the  minerals  is  present.  An  annual  application 
in  spring  of  500  pounds  per  acre  of  basic  formula 
No.  2  (p.  288)  will  furnish  sufficient  food  on  soils  of 
good  character,  though  on  lighter  soils  additional 
nitrogen  should  be  supplied,  preferably  in  forms  not 
too  active.  The  practice  of  applying  quick -acting 
nitrogen  early  in  the  spring,  after  plants  have  blos- 
somed, has  been  followed  with  great  success,  particu- 
larly upon  the  lighter  soils,  as  it  encourages  a  more 
complete  development  of  fruit,  though  it  should  be 
used  with  caution,  since  the  fruit  canes  of  both  the 


FERTILIZE  FOR  FRUIT,   NOT   WOOD  303 

present  year  and  those  which  provide  the  plant  for 
the  next  year  naturally  grow  in  the  same  bed,  and 
the  young  canes  may  not  mature  properly  if  too 
heavy   applications  of   nitrogen  are  made. 

CUERANTS    AND    GOOSEBERRIES 

These  are  crops  which,  under  average  conditions, 
are  seldom  heavily  fertilized,  though  fertilizing  is 
usually  followed  with  great  profit.  They  are  less 
likely  to  need  nitrogen  than  the  other  crops  men- 
tioned, and  a  too  heavy  fertilization  with  this  element 
has  a  tendency  to  encourage  the  development  of  mil- 
dew, the  disease  so  common  to  these  crops.  In  com- 
mon with  the  other  crops  mentioned,  they  should  be 
abundantly  supplied  with  the  minerals,  phosphoric 
acid  and  potash,  and  the  basic  formula  already  rec- 
ommended (p.  288)  may  be  used  in  all  cases  with 
profit  at  the  rate  of  500  to  1,000  pounds  per  acre. 
The  additional  nitrogen  needed  may  be  provided  by 
the  slow -acting  materials.  Many  growers  find  such 
waste  products  as  wool  and  hair  of  great  advantage 
in  the  growing  of   these  crops. 

GRAPES 

Grapes  are  more  exhaustive  as  a  crop  than  most  of 
the  fruit  crops,  largely  because  of  the  larger  total  crop 
harvested,  and  the  special  need  is  for  phosphoric  acid 
and  potash.  These  elements  may  be  supplied  by  the 
basic  formula  (p.  288),  and  very  liberal  dressings  are 


304  FERTILIZERS 

recommended, — from  1,000  to  2,000  pounds  per  acre 
annually, — after  the  bearing  period  begins.  On 
light  soils,  an  annual  spring  dressing  of  nitrate  of 
soda,  at  the  rate  of  200  pounds  per  acre,  is  also 
desirable,  in  order  to  encourage  rapid  and  large 
early  growth  of  leaf  and  vine,  though  this  dressing 
may  be  omitted  if  the  growth  of  clover  as  a  green 
manure  is  practicable.  The  latter,  however,  as  when 
used  in  connection  with  the  other  fruits  mentioned, 
should  not  be  allowed  to  mature,  but  rather  be 
plowed  down  early  in  the  season. 

The  main  point  in  the  fertilization  of  all  fruits  is 
to  provide  an  abundance  of  the  mineral  elements,  and 
to  give  particular  attention  to  fertilization  with  nitrog- 
enous materials.  It  must  be  remembered  that  it  is 
the  fruit,  not  the  wood,  that  constitutes  the  crop, 
and  that  all  the  energies  should  be  directed  toward 
the  development  of  such  a  tree  or  vine  as  will  best 
contribute   toward  this  end. 


CHAPTER  XV 

FERTILIZERS  FOR    VARIOUS  SPECIAL   CROPS 

In  addition  to  the  generally  familiar  crops  already 
described,  there  are  certain  special  ones,  not  distinct 
from  the  others  because  they  are  of  less  importance, 
but  rather  because  they  are  only  grown  in  certain 
localities. 

COTTON 

Among  these  special  crops,  cotton  takes  first  rank, 
because  it  is  one  of  the  leading  crops  of  the  country, 
occupying  wide  areas,  and  exercising  fully  as  great 
an  influence  upon  our  agricultural  prosperity  as  any 
other  of  our  American  staples. 

The  climate  suitable  for  the  growing  of  cotton  is 
confined  to  about  one -quarter  of  the  area  of  the  coun- 
try, and  in  this  area  it  occupies  a  more  important 
position  than  any  other  crop  grown  there. 

In  the  earlier  history  of  its  cultivation,  the  methods 
employed  were  not  such  as  to  encourage  the  largest 
yield.  In  the  first  place,  it  was  grown  on  the  poorer 
soils  rather  than  the  more  fertile,  and  after  it  had  been 
grown  consecutively  upon  the  same  lands  for  a  number 
of  years,  and  thus  rapidly  exhausting  them,  the 
planter,  instead  of  attempting  to  improve  the    lands, 

T  (305) 


306  FERTILIZERS 

either  by  better  methods  of  culture  or  by  the  use  of 
manures,  extended  the  areas  under  cultivation.  After 
the  civil  war,  when  it  became  still  more  necessary  to 
change  methods,  fertilizers  were  looked  to  as  the  main 
reliance,  rather  than  the  improvement  of  the  character 
of  the  soil,  either  by  judicious  rotation  or  by  manur- 
ing. The  results  secured  from  the  use  of  fertilizers  at 
this  time  were  so  generally  satisfactory  that  their  large 
and  indiscriminate  use  was  encouraged,  and  this,  with- 
out proper  attempts  at  the  improvement  of  the  soil  in 
other  respects,  hastened  the  time  when  such  use  did  not 
give  profitable  returns.  The  very  great  importance  of 
the  crop  to  the  agriculture  of  the  leading  cotton  states, 
and  the  necessity  of  better  methods  of  culture,  were  so 
fully  appreciated  that  a  scientific  study  of  the  crop  was 
then  entered  upon,  and  the  states  largely  interested 
planned,  through  the  aid  of  their  colleges  and  ex- 
periment stations,  a  wide  series  of  experiments,  which 
were  directed  toward  the  solution  of  the  problems 
connected  with  the  feeding  of  the  plant.  The  results  of 
these  experiments  have  been  fruitful  of  such  valuable 
information  as  to  warrant  practical  and  specific  sug- 
gestions which  have  a  wide  application,  and  which,  if 
followed,  will  result  in  the  improvement  of  the  soil  and 
in  the  economical  increase  in  crop. 

As  already  stated,  the  cotton  crop  is  not  an  ex- 
haustive one  in  one  sense,  though  the  methods  of 
practice  used  in  its  growth  have  been  wasteful,  and 
thus  have  given  rise  to  that  belief.  That  is,  a  large 
crop  of  cotton  does  not  remove  from  the  soil  a  very 
considerable    amount     of    the    fertilizer    constituents. 


IMPORTANCE   OF  PHOSPHOBIG  ACID  307 

The  following  amounts  are  contained  in  a  crop  yield- 
ing 300  pounds  of  lint  per  acre  :* 

Nitrogen 46  lbs. 

Phosphoric  acid 12  lbs. 

Potash 30  lbs. 

Fertilizers  for  Cotton 

In  regard  to  its  need  for  fertilizing,  cotton  may  be 
classed  with  the  cereals  rather  than  with  the  crops  al- 
ready discussed ;  and  like  the  cereals,  its  best  growth 
is  attained  when  properly  introduced  into  a  rotation 
with  other  crops,  and  the  annual  food  supply  arranged 
in  such  a  manner  as  to  contribute  to  the  larger  yield  of 
the  immediate  crop,  as  well  as  to  furnish  an  unused 
residue  which  will  provide  for  an  increase  in  the  yield 
of  the  succeeding  ones.  Of  the  constituents,  phos- 
phoric acid  seems  to  exercise  a  greater  influence  upon 
the  growth  and  development  of  the  cotton  plant  than 
any  other  element,  notwithstanding  the  fact  that 
smaller  amounts  are  contained  in  it  than  of  either 
nitrogen  or  potash.  That  is,  it  appears  that  the  plant 
must  have  an  abundance  of  available  phosphoric  acid 
at  its  command  in  order  that  the  other  constituents 
necessary  for  a  full  crop  may  be  freely  absorbed,  though 
on  the  soils  adapted  for  the  crop,  which  naturally  vary 
widely  both  in  their  general  and  special  physical  char- 
acteristics, but  are  poor  in  the  fertility  elements,  both 
nitrogen  and  potash  must  be  applied,  in  order  that 
maximum  crops  may  be  obtained. 


♦Farmers'  Bulletin  No.  14,  Department  of  Agriculture. 


308  FERTILIZERS 

On  the  whole,  therefore,  though  the  "intensive" 
system  is  not  generally  practieed,  fertilizers  furnishing 
all  of  the  constituents  are  superior  to  those  which  fur- 
nish but  one  or  two;  yet  when  proper  rotations  are 
practiced  and  leguminous  crops  are  grown  for  the  pur- 
pose of  improving  the  physical  character  of  the  soil,  as 
well  as  increasing  its  content  of  nitrogen,  the  percent- 
age of  this  element  introduced  into  the  fertilizer  may 
be  very  largely  reduced. 

The  conclusions  that  have  been  arrived  at  by  the 
experiments  conducted  in  the  various  states  have  been 
very  fully  set  forth  in  various  publications,*  and  the 
following  statements  drawn  from  these  indicate  what 
are  believed  to  be  the  advantages  derived  from  the  right 
use  of  fertilizers,  and  the  best  methods  to  be  observed: 

"The  cotton  plant  responds  promptly,  liberally  and 
profitably  to  judicious  fertilization.  The  maturation 
of  the  crop  may  be  hastened,  and  the  period  of 
growth  from  germination  to  fruiting  may  be  so  short- 
ened as  to  increase  the  climatic  area  in  which  it  may 
be  profitably  grown.  It  should  be  assigned  to  a 
place  in  a  rotation  system.  One  of  small  gi-ain,  corn 
(with  peas)  and  cotton,  is  well  suited  for  the  con- 
ditions prevailing  in  the  cotton  belt,  and,  as  with 
other  crops,  the  results  derived  from  the  use  of 
fertilizers  for  this  crop  are  much  enhanced  by  the 
proper    preparation    of    the    soil.     It    pays    to    bring 


♦Farmers'  Bulletins,  Nos.  14  and  48,  Department  of  Agriculture.  Oflfiee  of 
Experiment  Stations,  Bulletin  No.  33,  Department  of  Agriculture.  Various 
bulletins  issued  by  the  Georgia,  South  Carolina  and  Louisiana  Experiment 
Stations. 


FORMULAS  FOR   COTTON  309 

up  the  cotton  lands  by  mechanical  treatment, 
and  especially  by  introducing  organic  matter.  The 
renovating  crops,  especially  the  cow  pea,  are  very 
profitably  employed  as  adjuncts  to  the  fertilization 
of  the  crop  itself.  On  the  majority  of  soils,  too,  it  is 
advisable,  and  more  generally  proves  profitable,  to  use 
a  complete  fertilizer,  rather  than  one  containing  one 
or  two  of  the  constituents;  and  of  the  forms  of  nitro- 
gen, organic  (vegetable  and  animal)  is  best  suited 
to  the  cotton,  if  one  form  alone  be  used,  although 
nitrate  of  soda  is  probably  nearlj^  if  not  quite,  of 
equal  value.  The  relative  advantages  of  various  pro- 
portions of  the  different  forms  have,  however,  not  yet 
been  fully  determined ;  hence  the  use  of  a  mixture 
of  the  best  is  a  safe  plan,  the  proportions  to  be 
determined  by  their  relative  cost.  In  the  case  of 
phosphoric  acid,  superphosphate  is  to  be  preferred  to 
to  materials  of  an  organic  or  mineral  nature,  which  are 
not  immediately  available.  Of  the  potash  salts,  no 
particular  difference  is  observed  in  the  use  of  the 
different  forms.  The  form  to  be  secured  is  to  be 
based   upon   the   price   of    the   different   forms." 

Formulas  for   Cotton   Fertilizers 

While  the  most  judicious  proportions  of  soluble 
phosphoric  acid,  of  potash  and  of  nitrogen  in  a  com- 
plete fertilizer  cannot  be  said  to  have  been  determined 
with  entire  accuracy,  the  carefully  conducted  experi- 
ments of  both  the  Georgia  and  South  Carolina  sta- 
tions indicate  that  for  general  use  1  part  of  nitrogen, 


310  FERTILIZERS 

1  of  potash,  and  2%  or  3  of  phosphoric  acid  in- 
dicate the  best  proportions.  The  amount  of  fer- 
tilizer that  may  be  profitably  used  very  naturally 
varies  widely,  though  medium  rather  than  very  large 
dressings  are  recommended,  not  so  much  because  the 
plant  under  good  soil  conditions  could  not  appropriate 
and  use  to  advantage  large  amounts,  but  because  on 
the  whole,  soils  used  for  cotton  are  peculiarly  lacking 
in  those  qualities  which  enable  the  proper  distribu- 
tion and  appropriation  of  the  larger  quantity.  For 
those  soils,  then,  the  amounts  per  acre  indicated  by 
the  Georgia  Experiment  Station  are,  annually  — 

Nitrogen 20  lbs. 

Available  phosphoric  acid 70     " 

Potash 20     " 

The    South    Carolina    Experiment    Station    recom- 
mends an  application   per  acre  of  — 

Nitrogen 20  lbs. 

Available  phosphoric  acid 50     " 

Potash 15     " 

or,  as  suggested  by  the  Georgia  Experiment  Station, 
perhaps  a  fertilizer  containing  — 

Nitrogen 3  % 

Phosphoric  acid  (soluble) 9  % 

Potash 3  % 

applied  at  the  rate  of  700  pounds  per  acre,  would  be 
approximately  the  best  amounts  to  use  under  ordinary 
circumstances. 


ADVANTAGES   OF  HOME  MIXTURES  311 

Method   of  Application 

The  fertilizer  should  be  applied  in  the  drill  at  the 
time  of  planting,  and  at  the  depth  of  not  more  than 
three  inches,  and  well  mixed  with  the  soil.  In 
most  cases  it  is  best  to  apply  all  of  the  fertilizer  in 
one  application  rather  than  in  fractional  applications, 
though  with  lands  in  superior  condition  profitable 
applications  may  be  made  again  at  the  second  plow- 
ing. Owing  to  the  nearness  of  the  cotton  belt  to 
the  supplies  of  superphosphate,  and  to  the  cheap  sup- 
plies of  cotton -seed  meal,  the  only  fertilizer  neces- 
sary to  import  is  potash.  Hence  it  has  become  a 
practice  in  most  sections  for  the  planter  to  make  his 
own  formulas,  using  his  own  supplies  of  phosphoric 
acid  and  nitrogen;  and  home  mixtures,  made  up  of 
acid  phosphate,  cotton -seed  meal  and  muriate  of 
potash,  or  kainit,  are  largely  used  to  supply  the 
demands.  The  following  formula  is  an  example  of  a 
good  mixture  : 

Acid  phosphate 1,200  lbs. 

Cotton-seed  meal 600     " 

Kainit 200     " 

The  formula  containing  — 

Nitrogen 3  % 

Phosphoric  acid 9  % 

Potash 3  % 

is  also  recommended,  since  an  application  of  700 
pounds  per  acre  will  furnish  the  amounts  and  propor- 
tions of   the  elements  indicated   as   the   maximum   by 


312  FERTILIZERS 

the  Georgia  station.  This  formula  is  also  well  suited 
for  corn,  if  introduced  into  a  rotation  as  previously 
suggested. 

TOBACCO 

Tobacco  is  another  special  crop  grown  only  in  cer- 
tain localities,  favored  either  by  reason  of  climate  or 
character  of  soil,  or  both.  It  is,  however,  a  very 
important  crop  in  this  country,  and  one  which  requires 
very  careful  attention  in  reference  to  the  amounts  and 
kinds  of  fertilizers  applied,  because  the  fertilization 
exercises  an  influence  upon  both  the  yield  and  quality 
of  the  crop.  It  is  an  exhaustive  crop,  drawing  heavily 
upon  both  nitrogen  and  potash.  A  crop  yielding  1,000 
pounds  of  leaf  per  acre  will  contain,  in  round  numbers, 
67  pounds  of  nitrogen,  9  of  phosphoric  acid  and  85  of 
potash  :  amounts  equivalent  in  nitrogen  to  over  400 
pounds  of  nitrate  of  soda,  of  phosphoric  acid  equiva- 
lent to  75  pounds  of  acid  phosphate,  and  of  potash 
equivalent  to  170  pounds  of  muriate  of  potash.  It  is 
a  fact,  too,  that  tobacco  of  the  best  quality,  or  that 
best  suited  for  cigar  wrappers,  can  be  grown  to  ad- 
vantage only  on  light,  sandy  soils, — those  not  natur- 
ally well  supplied  with  the  fertilizing  constituents. 
Thus,  if  large  crops  are  to  be  secured,  the  soil  must 
receive  liberal  supplies  of  food  from  artificial  sources. 

The  Influence   of  Fertilizers  on    the    Quality   of 
the    Crop 

A  point  of  great  importance  in  the  fertilizing  of 
tobacco,  is   the   influence  of    the   constituents   applied 


FERTILIZERS  INFLUENCE   QUALITY  313 

on  the  marketable  quality  of  the  crop,  as  for  certain 
purposes,  especially  for  the  manufacture  of  cigars  and 
cigarettes,  the  tobacco  must  possess  peculiar  charac- 
teristics in  order  to  bring  the  highest  price  in  the 
market.  In  other  words,  in  the  growing  of  this  crop, 
as  is  the  case  in  many  others,  both  the  yield  and 
quality  must  be  taken  into  consideration,  and  frequently 
the  latter  point  is  of  quite  as  much  importance  as  the 
former,  though  a  reasonable  yield  must  be  secured 
before  the  influence  of  quality  is  of  practical  signifi- 
cance. The  quality  of  the  leaf  is  believed  to  be 
influenced  chiefly  by  the  constituent  potash,  though 
many  growers  object  to  the  use  of  various  nitrogenous 
and  phosphatic  materials,  believing  that  they,  too, 
exercise  a  decidedly  unfavorable  influence  upon  the 
quality  of  the  leaf.  Careful  experiments,  however,  do 
not  justify  many  of  the  opinions  of  growers  and  dealers 
regarding  the  effect  of  the  different  materials  upon  the 
quality  of  wrapper  tobacco. 

The  main  points,  therefore,  in  the  fertilizing  of 
tobacco,  are  to  see  to  it  that  a  sufl&cient  quantity  of 
plant -food  is  applied  in  order  to  secure  the  largest 
possible  yield  consistent  with  quality,  and  second,  to 
avoid  the  use  of  such  constituents  as  are  positively 
injurious. 

The  Conclusions  from  Connecticut  Experiments 

Experiments  in  the  application  of  fertilizers  to  to- 
bacco have  been  carried  out  at  the  Connecticut  Exper- 
iment Station  with  great  care  and  skill  for  a  number 


314  FERTILIZERS 

of  consecutive  years.*  They  lead  to  the  conclusion 
that  "there  is  no  'best'  tobacco  fertilizer,  or  'best' 
formula  for  all  seasons,  even  on  the  same  soil.  A 
formula  or  a  form  of  plant -food  which  in  one  season 
gives  the  leaf  a  somewhat  better  quality  than  any 
other,  may,  perhaps  the  next  year  and  on  the  same 
soil,  prove  inferior  to  others,  for  reasons  which  can 
only  be  surmised. 

"Nevertheless,  by  comparing  the  effects  of  these 
fertilizers  for  a  term  of  years,  it  appears  that  certain 
ones  are,  on  the  whole  and  generally  speaking,  more 
likely  to  impart  a  perfectly  satisfactory  quality  to  the 
leaf  than  certain  others. 

"It  is  doubtless  true  of  tobacco,  as  of  other  crops, 
that  the  liberal  but  not  greatly  excessive  supply  of 
readily  available  plant -food  yearly  required  to  insure  a 
paying  crop  may  be  given  in  a  variety  of  forms  with 
equally  good  results,  on  the  average  of  one  season  with 
another,  and  that,  indeed,  occasional  changes  in  the 
form  of  nitrogen  and  potash  supplied  may  be  a  distinct 
advantage,  avoiding  always  any  considerable  quantity 
of  those  things,  as  chlorin,  and  sulfuric  or  other  free 
acids,  which  experience  has  shown  may  damage  the 
leaf." 

These  conclusions  in  regard  to  the  kind  and  quantity 
of  fertilizing  constituents  required  for  the  growing  of 
tobacco  of  good  quality  confirm  those  arrived  at  by 
experiments  elsewhere,  and  the  suggestions  made  are 
sufficiently  definite   to  guide    in  the   use  of   fertilizers 


♦Connecticut  Agr.  Exper.  Sta.,  Annual  Report,  1897,  Part  IV.,  page  255. 


DESIRABLE  FORMS  315 

• 

for  this  crop.  In  brief,  therefore,  the  tobacco  crop 
must  be  provided  with  an  abundance  of  all  of  the  fer- 
tilizer elements  derived  from  readily  available  forms, 
and  free  from  those  constituents  known  to  exercise  an 
unfavorable  influence  upon  the  quality  of  the  product, 
in  order  that  satisfactory  yields  of  good  quality  may  be 
secured. 

Form    of  the    Constituents 

It  has  not  been  shown  that  one  form  of  nitrogen 
is  superior  to  another  under  all  circumstances,  or  in 
other  words,  that  one  form  of  nitrogen, — as,  for 
example,  ammonia  or  nitrate,  or  any  particular  form 
of  organic  nitrogen,  vegetable  or  animal, — is  superior 
to  all  others,  but  rather  that  any  or  all  of  the  good 
forms  may  be  used  in  a  mixture,  provided  a  sufficient 
abundance  is  present  to  insure  a  maximum  yield, 
though  not  so  large  an  amount  in  excess  of  the 
minerals  as  to  encourage  a  rank,  coarse  growth.  The 
phosphoric  acid  should  be  in  available  forms,  and  if 
in  these  forms,  must  naturally  be  drawn  largely  from 
superphosphates.  The  potash  should  in  all  cases  be 
drawn  from  sources  free  from  chlorids.  A  fertilizer, 
therefore,  which  contains  the  nitrogen,  either  in  good 
organic  forms,  as  cotton -seed  meal  or  blood,  or  a  mix- 
ture of  these  organic  forms  with  ammonia  or  nitrate 
in  not  too  large  amounts,  which  contains  the  phos- 
phoric acid  in  a  soluble  form,  and  potash  derived 
from  products  free  from  chlorids, — as  from  high-grade 
sulfate,    or    from   a   carbonate,    or    from     cotton -hull 


316  FERTILIZERS 

ashes,   if    these  are    obtainable, — may  be  regarded    as 
well  adapted  for  the  crop. 

Amounts   to  Apply 

An  annnal  dressing  which  will  furnish  100  pounds 
of  nitrogen,  75  of  phosphoric  acid  and  150  of  potash 
per  acre  may  be  regarded  as  a  minimum  for  soils  of 
medium  quality.  On  lighter  soils  heavier  applications 
should  be  made,  and  on  soils  previously  well  enriched 
with  the  fertilizer  constituents,  the  dressing  may  be 
somewhat  less.  It  must  be  remembered,  however,  that 
it  is  not  economical,  from  the  standpoint  of  either 
yield  or  quality,  to  be  too  sparing  in  the  applica- 
tion of  fertilizers,  because  the  plant  requires  large 
amounts  of  both  nitrogen  and  potash,  and  because  it 
is  essential  that  the  plant  should  have  a  reasonable 
excess  of  these  at  its  command,  in  order  to  overcome 
as  far  as  possible  any  unfavorable  seasonal  conditions 
that  may  occur. 

In  the  Connecticut  experiments  already  referred  to, 
amounts  greatly  in  excess  of  those  suggested  have 
been  used  with  advantage.  In  Kentucky  and  Vir- 
ginia, on  soils  naturally  richer,  smaller  amounts  have 
given  quite  as  good  results.  It  is  likely,  however, 
that  upon  the  very  light  soils  of  certain  of  the 
states  in  which  tobacco  of  high  quality  is  grown, 
notably  Florida,  considerably  increased  amounts  may 
be  used  with   profit. 

As  sources  of  at  least  part  of  the  nitrogen  and 
potash     in    the    southern    states    particularly,    cotton- 


FERTILIZERS  FOR  SUGAR-CANE  317 

seed  meal  and  cotton -hull  ashes  are  recommended, 
because  readily  obtainable.  These  forms  have  been 
found  to  be  good,  and  they  may  be  obtained  as 
cheaply  as  other  forms  as  well  as  more  conveniently. 

SUGAR-CANE 

Another  special  crop,  confined  largely  to  one  state, 
Louisiana,  is  sugar-cane,  and  perhaps  no  other  one 
crop  has  in  this  country  received  such  careful  study 
in  reference  to  its  needs  for  plant-food.  The  Sugar 
Experiment  Station  of  that  state  has  for  twelve  years 
conducted  a  series  of  systematic  experiments  designed 
to  answer  the  questions  as  to  what  the  needs  are 
for  nitrogen,  phosphoric  acid  and  potash ;  and  the 
results  of  this  work  thus  far  secured  furnish  sugges- 
tions in  reference  to  fertilization,  which  will,  if  care- 
fully followed,  undoubtedly  result  in  the  production 
of  better  crops  than  are  grown  under  present  systems. 
Fertilizers  are  clearly  needed,  and  their  right  use  is  a 
profitable  practice,  though,  as  stated  by  Doctor  Stubbs, 
"many  ascribe  the  failure  from  their  use  to  the  worth- 
lessness  of  the  fertilizer,  when  it  should  be  ascribed 
to  some  defection  of  the  soil,  rendering  it  incapable 
of  appropriating  the  applied  fertilizer." 

The  chief  conclusions  in  reference  to  fertilizers 
for  sugar-cane  in  Louisiana,  so  clearly  set  forth  bj'- 
Doctor  Stubbs  in  this  report,*  are  here  summarized, 
as   it   is   believed    that   the   underlying   principles   are 


*  "Sugar-Cane,"  Vol.  I,   Sugar  Experiment   Station,  Audubon   Park,   New 
Orleans,  La. 


318  FERTILIZERS 

applicable  elsewhere,  though  naturally  their  use  must 
be  modified  to  suit  individual  cases. 

The,  Needs   of  the   Plant  as  Indicated   by   the 
Louisiana  Experiments 

"An  examination  of  the  cane  plant  shows  that  a 
crop  of  30  tons  will  remove,  in  round  numbers,  102 
pounds  of  nitrogen,  45  of  phosphoric  acid  and  65  of 
potash.  It  is,  therefore,  a  relatively  exhaustive  crop, 
and  unless  the  physical  conditions  are  perfect,  even 
good  soils  should  receive  considerable  dressings  of  the 
constituents,  if  the  fertility  is  to  be  maintained. 

"The  results  secured  thus  far  in  the  experiments 
referred  to  demonstrate  that  the  soil  needs  nitrogen 
and  phosphoric  acid  particularly,  in  order  to  grow 
cane  successfully,  while  thus  far,  no  results  of  any 
character,  either  in  the  increased  sugar  content  or 
tonnage  per  acre,  have  been  visible  from  the  use 
of  any  form  of  potash  upon  the  alluvial  lands  of 
the  lower  Mississippi.  Several  forms  of  potash, 
notably  the  carbonate,  and  ashes  of  cotton -seed  hulls, 
have  rather  decreased  the  yield  of  cane  and  injured 
the  physical  qualities  of  the  soil  by  causing  it 
to  'run    together.' 

"In  reference  to  the  form  and  amount  of  nitro- 
gen, it  has  been  shown  that  sulfate  of  ammonia 
gives  slightly  better  results  than  any  other  form, 
though  its  higher  cost  gives  no  advantage  over  those 
costing  less,  while  cotton -seed  meal  comes  next,  fol- 
lowed by  dried  blood  and  nitrate  of  soda.     In  refer- 


LOUISIANA   EXPEBIMENTS  319 

ence  to  the  amount  of  nitrogen  to  be  applied,  ,it  is 
shown  that  not  less  than  twenty-four  pounds  nor  more 
than  forty -eight  pounds  per  acre  should  be  applied. 
Naturally,  different  soils  and  different  kinds  of 
cane  would  vary  in  their  requirements  for  this 
element,  and  the  amount  needed  would  also  be  in- 
fluenced by  the  method  of  growing  the  crop  :  whether 
upon  'succession'  land — that  is,  upon  soils  upon  which 
a  crop  of  stubble  cane  has  just  been  taken  off,  and 
which  has  been  in  cane  for  a  number  of  years  with- 
out the  intervention  of  a  leguminous  crop  between  to 
restore  the  nitrogen  —  or  whether  upon  pea- vine  land, 
upon  which  the  plant  cane  is  grown  the  first  year, 
stubble  cane  the  second,  and  corn  and  cow  peas  the 
third  year.  This  system  of  rotation,  which  intro- 
duces a  leguminous  crop  into  it,  not  only  improves 
the  physical  quality  of  the  soil,  but  enables  a  con- 
siderable accumulation  of  nitrogen,  frequently  over 
one  hundred  pounds  per  acre.  The  pea -vine  lands, 
put  in  plant  cane  on  account  of  their  excellent  physi- 
cal condition,  not  only  yield  up  readily  the  nitrogen 
stored  up  by  the  pea,  but  can  also  assimilate  larger 
quantities  of  plant-food  applied  as  fertilizer.  Hence, 
such  cane  usually  makes  large  crops.  Since  nitrogen 
is  the  chief  ingredient  taken  from  the  soil  by  a  crop 
of  cane,  it  follows  that  with  each  successive  crop  of 
cane  grown  on  the  land  without  the  interjection 
of  'the  leguminous  nitrogen  there  arises  an  increased 
demand  for  nitrogen.  Hence,  stubble  cane  requires 
larger  quantities  than  plant  cane,  and  the  older  the 
stubble,  the  larger  its  requirements  for  this  element." 


320  FEBTILIZERS 

In  reference  to  phosphoric  acid,  the  results  so  far 
indicate  positively  the  value  of  this  element  in  fer- 
tilizers for  sugar-cane  on  these  soils,  but  the  demand 
for  this  ingredient  is  small  in  comparison  to  that  for 
nitrogen,  36  pounds  per  acre  being  ample  for  the  crop. 
The  results  further  show  that  the  soluble  forms  of 
phosphoric  acid  are  preferred.  Inasmuch  as  the  legu- 
minous crop  does  not  add  to  the  store  of  phosphoric 
acid  in  the  soil,  it  is  equally  needed  by  both  plant  and 
stubble  cane. 

While  potash  has  not  been  shown  to  be  needed  on 
the  land  upon  which  the  experiments  were  conducted, 
because  of  the  abundance  of  potash  contained  in  the 
soil,  after  continuous  cropping  of  these  and  on  lighter 
soils  this  element  should  be  included  in  the  fertilizer. 

The  Application  of  Fertilizers 

For  plant  cane,  a  small  quantity  of  readily  available 
fertilizer  directly  under  and  near  the  cane  is  highly 
beneficial,  as  it  provides  food  also  for  the  sucker, 
which,  with  food  at  hand,  is  greatly  aided  in  develop- 
ing a  healthy  sucker,  and  thus  the  entire  plant  is  given 
a  vigorous  send-off  in  youth.  It  is  necessary,  to 
give  a  good  start  to  a  young  plant,  to  withhold  manures 
until  a  stand  is  secured,  though  when  cane  is  planted 
during  the  fall  and  winter,  as  it  is  in  Louisiana,  the 
danger  of  loss  by  leaching  must  be  reckoned  upon,  and 
the  exact  amounts  to  be  applied  at  that  time  regulated 
by  the  judgment  of  the  planter.  Usually  the  more 
perfect  the  incorporation  of   a  manure  in  the  soil  the 


PROPER  APPLICATION  321 

better  the  results  to  be  expected,  but  in  this  ease  it 
should  be  deposited  in  a  drill  and  well  mixed  witti  the 
soil.  In  the  spring,  after  the  cane  is  closely  off-barred, 
the  fertilizer,  if  not  applied  at  planting,  should  be 
scattered  on  both  sides  of  the  plant  from  the  center  of 
the  row  to  the  off-barred  furrow.  Hence,  in  reversing 
the  furrow,  the  manure  is  covered,  and  subsequent  culti- 
vation will  mix  the  latter  with  the  soil.  If  the  cane  has 
received  the  first  application  at  planting,  the  second  one 
should  be  given  in  May,  on  both  sides  of  the  row. 
The  stubble  cane  should  not  be  fertilized  very  long 
before  each  sprout  has  sent  out  its  ow^n  rootlets,  since 
prior  to  this  no  good  could  be  accomplished,  and  there 
would  be  a  waste  of  manure. 

MISCELLANEOUS    CROPS 

Other  crops  of  importance  for  which  the  need  of 
fertilizers  is  frequently  apparent  include  sorghum, 
buckwheat,  peanuts,  roses  and  herbaceous  plants, 
lawns,  grasses,  and  plant -house  vegetables.  These 
are,  of  course,  similar  to  those  alreadj'  described, 
since  their  best  development  requires  that  they  shall 
be  well  supplied  with  the  fertilizing  constituents, 
nitrogen,  phosphoric  acid  and  potash,  though  their 
special  needs  in  this  respect  have  not  been  so  fully 
investigated  as  the  other  crops  dealt  with  in  this 
chapter.  The  discussion  of  their  requirements  is, 
therefore,  necessarily  brief,  and  the  suggestions  made 
are  of  a  general  rather  than  a  special  character,  though 
they  may  serve  as  a  safe   guide. 

u 


322  FERTILIZERS 

Sorghum 

Sorghum  is  grown  both  for  forage  and  for  sugar, 
and  its  fertilization  should  be  discussed  from  these  two 
standpoints.  If  grown  for  forage,  the  fertilization 
should  be  more  liberal  and  of  a  different  character 
than  if  for  sugar,  as  the  object  is  the  largest  yield  of 
succulent  food  rather  than  the  highest  yield  of  sugar, 
and  the  yield  of  sugar  is  not  always  consistent  with  the 
highest  yield  of  cane.  For  forage,  therefore,  the  ferti- 
lizer recommended  for  maize  forage  (p.  242)  is  well 
adapted  for  sorghum  on  soils  in  a  good  state  of  fertility, 
though  since  the  plant  is  very  slow  to  start,  its  early 
growth  is  stimulated  if  a  larger  amount  of  readily 
available  nitrogen  is  used  than  is  desirable  for  corn, 
particularly  on  soils  of  medium  fertility,  and  which 
have  not  been  previously  well  fertilized.  If  grown  for 
sugar,  too  much  nitrogen  must  be  avoided,  since  an 
excess  of  this  element  in  the  fertilizer  causes  an  im- 
perfect ripening,  and  consequently  a  higher  percent- 
age of  non-crystallizable  sugar  in  the  cane  ;  though 
if  quickly  available  forms  are  used,  as  nitrate,  am- 
monia, or  dried  blood,  which  may  be  absorbed  by  the 
plant  early  in  the  season,  a  larger  amount  may  be 
applied  with  safety  than  if  the  poorer  forms  are  used. 
Of  the  three  constituents,  potash  in  the  form  of 
muriate  seems  to  be  the  one  exercising  the  greatest 
influence  upon  the  yield  of  sugar,  hence  it  should 
always  be  introduced  in  considerable  amounts  in  fer- 
tilizers  for    sorghum.*      A    fertilizer    furnishing    20 


♦Report  for  1886,  New  Jersey  Agricultural  Experiment  Station. 


BUCKWHEAT  323 

pounds  of  nitrogen,  35  of   phosphoric  acid  and  60  of 
potash  per  acre  will  meet  the  needs  on  average  soils. 

BucTiwheat 

Buckwheat  is  frequently  grown  upon  the  poorer 
soils  of  the  farm.  It  is  a  crop  well  adapted  to  moun- 
tain lands,  and  as  a  preparatory  crop  in  the  breaking 
of  new  lands.  It  has  not  been  carefully  studied  in 
reference  to  its  needs  for  plant -food,  though  phosphoric 
acid  seems  to  be  the  constituent  more  particularly 
required  than  the  others.  Its  need  of  nitrogen  is 
marked,  yet  because  its  entire  growth  and  development 
are  made  during  the  months  of  July  and  August,  when 
conditions  are  most  favorable  for  soil  activities,  heavy 
nitrogenous  fertilization  is  not  to  be  recommended, 
except  when  grown  on  very  light  soils,  or  those  defi- 
cient in  vegetable  matter.  The  moderate  use  of  fer- 
tilizers rich  in  minerals,  and  which  contain  nitrogen  in 
quickly  available  forms,  result  favorably,  not  only  in 
increasing  the  yield,  but  assist  materially  in  maturing 
the  crop,  a  matter  of  great  importance.  A  fertilization 
with  25  pounds  per  acre  each  of  phosphoric  acid  and 
potash  and  10  of  nitrogen  may  be  regarded  as  a  good 
one  for  soils  of  medium  character. 

Peanut 

The  peanut  is  a  leguminous  plant,  and,  like  others 
of  this  family,  is  not  specifically  benefited  by  nitrogen, 
but  responds  readily  to  liberal  dressings  of  phosphoric 


324  FERTILIZERS 

acid  and  potash.  The  fertilization  suggested  for  green 
manure  crops,  namely,  a  mixture  of  three  parts  acid 
phosphate  and  one  part  muriate  of  potash,  or  equal 
parts  of  acid  phosphate  and  kainit,  may  be  used  for 
this  crop  with  great  advantage.  The  applications,  if 
frequently  made,  need  not  exceed  300  to  400  pounds 
per  acre.  Like  other  leguminous  crops,  it  is  specifically 
benefited  by  lime,  medium  dressings  of  which  (20 
bushels  per  acre)  should  be  made  at  least  once  in  four 
years.  In  the  districts  in  which  this  crop  is  success- 
fully grown,  lime  marls  are  frequentlj^  obtainable  at 
slight  expense,  and  may  be  used  with  great  advantage. 

Roses,  and  Other  Flotvering  Plants 

In  the  growing  of  roses  and  other  herbaceous 
plants,  of  which  the  flowers  constitute  the  crop,  great 
care  is  usually  taken  in  the  preparation  of  the  soil, 
and  natural  soils  are  seldom  used.  Notwithstanding 
the  richness  of  the  prepared  soils,  the  crops  are  bene- 
fited by  the  addition  of  commercial  fertilizers,  partic- 
ularly those  phosphatic  in  their  nature.  Ground  bone 
is  especially  useful,  since  it  furnishes  both  nitrogen 
and  phosphoric  acid  in  slowly  available  forms,  and 
usually  sufficient  nitrogen  to  meet  the  needs  of  the 
plant,  as  excessive  quantities  of  this  element  cause  a 
too  vigorous  and  rank  growth  of  foliage,  which  is 
not  accompanied  by  profuse  flowering.  A  good  mix- 
ture for  the  prepared  soils,  therefore,  may  consist 
of  four  parts  of  ground  bone  and  one  part  of  mu- 
riate of    potash,  which  may  be  applied   at  the  rate  of 


FLOWERS  AND  LAWNS  325 

four  pounds  per  square  rod  of  area,  and  well  worked 
into  the  soil  previous  to  setting  the  plants.  The  after- 
fertilization  may  contain  a  larger  portion  of  the  sol- 
uble phosphoric  acid,  which  is  more  readily  distrib- 
uted. The  need  for  nitrogen  is  indicated  by  a  yel- 
low, rather  than  a  bright  green  color  in  the  foliage. 
Nitrogen  may  be  supplied  by  light  dressings  (%  to  1 
pound  per  square  rod)  of  the  active  forms  of  this 
element,  preferably  nitrate  of  soda,  because  of  its  ready 
distribution.  In  the  preparation  of  soils  for  these 
plants  in  the  house,  the  mixture  may  be  applied  at  the 
rate  of  2  pounds  for  every  100  square  feet  of  surface, 
the  after  application  to  consist  of  the  more  soluble 
forms  as  recommended  for  the  hardy  plants.  An  even 
mixture  of  nitrate  of  soda  and  acid  phosphate  may  be 
used  at  the  rate  of  one  pound  for  every  100  square  feet 
of  surface  once  in  two  weeks,  if  the  plants  do  not 
show  vigorous  growth. 

Lawn  Grasses 

The  fertilization  of  lawns  is  also  important  in  a 
sense,  because  proper  fertilizing  obviates  the  necessity 
of  the  home  manures,  which,  although  excellent  as 
sources  of  the  constituents,  are  frequently  offensive. 
The  use  of  manure  also  involves  considerable  labor, 
both  in  the  application  and  the  consequent  removal 
of  the  coarse  part  in  the  spring,  besides  resulting  in 
the  introduction  of  weed  seeds.  In  the  preparation 
of  the  soil  for  a  lawn,  it  must  be  supplied  with  an 
abundance  of  all  of  the  necessary  fertilizer  ingredients 
previous  to  seeding,  and  of  these  phosphoric  acid  and 


326  FERTILIZERS 

nitrogen  are  especially  important.  Too  great  an  ex- 
cess of  potash  encourages  the  development  of  the 
clovers  rather  than  the  grasses.  This  preparatory 
fertilizer  may  contain  the  more  slowly  available  forms 
of  nitrogen  and  phosphoric  acid.  Ground  bone  is  an 
excellent  source  of  these  elements,  and  a  mixture  of 
five  parts  of  ground  bone  and  one  of  muriate  of  pot- 
ash makes  an  excellent  dressing.  This  may  be  ap- 
plied at  the  rate  of  five  pounds  per  square  rod,  and 
thoroughly  worked  into  the  soil.  The  after -fertiliza- 
tion may  consist  chiefly  of  nitrogen,  preferably  as  a 
nitrate,  since  its  ready  solubility  permits  of  its  free 
penetration  into  the  lower  layers,  which  encourages 
a  deeper  root  system,  and  thus  greater  resistance 
to  drought. 

The  top -dressings  with  nitrate  of  soda  should  con- 
sist of  light  fractional  dressings,  rather  than  of  large 
amounts  at  one  time.  One -half  pound  per  square 
rod,  twice  or  thrice  during  the  season  —  the  first  as 
soon  as  the  grass  is  well  started  in  the  spring,  and 
preferably  immediately  preceding  a  rain  —  will,  if  the 
land  has  been  previously  well  prepared,  be  sufficient. 
To  facilitate  the  distribution  of  the  nitrate,  as  well  as 
to  supply  a  sufficient  abundance  of  phosphoric  acid, 
it  may  be  mixed  with  equal  parts  of  ground  bone. 

Forcing -house  Crops 

A  rich  garden  loam,  to  which  a  considerable  pro- 
portion of  stable  manure  —  one -third  to  one -half  the 
bulk  —  has    been    added,   is    the    usual    type    of    soils 


VEGETABLES   UNDER   GLASS  327 

for  such  crops  as  tomatoes,  lettuce,  radishes  and 
cucumbers  under  glass.  The  addition  of  fertilizers 
to  these  is  seldom  advisable.  It  has  been  demon- 
strated, however,  that  such  mixtures  are  not  essential, 
and  that  the  crops  may  be  profitably  and  successfully 
grown  in  mediums  which  contain  no  plant -food,*  if 
supplied  with  an  abundance  in  available  forms  from 
artificial  sources.  In  the  absence  of  good  manure, 
which  is  the  chief  expense,  a  reasonably  fertile  loamy 
soil  may  be  used  for  filling  the  beds,  in  which  at  the 
time  of  filling  may  be  mixed,  for  each  100  square  feet 
of  surface,  one-half  pound  of  nitrate  of  soda,  one 
pound  of  acid  phosphate,  one  pound  of  ground  bone, 
and  one -half  pound  of  muriate  of  potash.  This  appli- 
cation will  be  suf&cient  to  supply  the  needs  of  the 
plants  for  food  until  growth  is  well  started,  after 
which  they  should  be  fertilized  at  least  once  each  week 
with  one -quarter  of  a  pound  of  nitrate  of  soda  for 
every  100  square  feet  of  surface  area,  and  with  the 
mineral  fertilizers  at  the  rate  of  one  pound  of  acid 
phosphate  and  one -half  pound  of  muriate  of  potash 
every  two  weeks.  These  may  be  applied  in  solution, 
or  evenly  distributed  over  the  surface  of  the  soil,  and 
worked  in  before  watering.  The  amounts  to  apply 
should  always  be  governed  by  the  judgment  of  the 
grower.  There  is  less  danger  from  the  application 
of  too  much,  if  properly  used,  than  is  commonly 
supposed. 


♦Connecticut  State  Experiment  Station  Reports  for  1895,  1896  and  1897. 


INDEX 


Actual  potash.    See  potash. 

Agricultural  salt,  117. 

Agricultural  value  of  a  fertilizer, 
measured  by  value  of  increased  crop 
produced,  152,  and  availability  of  its 
constituents,  1.53;  distinct  from  com- 
mercial value,  153. 

Alfalfa,  character  of  its  growth,  252; 
its  fertility  content,  253;  fertiliza- 
tion, 253. 

Ammonia,  its  formation  in  the  soil, 
50;  a  better  form  than  organic  nitro- 
gen, 50;  its  commercial  form,  50. 
See  also  sulfate  of  ammonia. 

Ammonite,  its  composition,  41;  how 
obtained,  42. 

Analysis  of  fertilizers,  how  to  inter- 
pret, 149;  indicates  whether  fertilizer 
is  high  or  low-grade,  149;  does  not 
always  show  the  source  of  the  ele- 
ments, 149. 

Animal  matter.    See  ammonite. 

Apatite.  69. 

Apples,  soil-exhaustion  from  growing 
290;  fertilization,  291-3;  New  York 
(Cornell)  experiments,  290. 

Apricots,  fertilization,  299. 

Artificial  fertilizers,  history  of  their 
use,  28;  need  of,  30;  made  necessary 
by  increase  in  cost  of  labor,  30 ;  by 
demands  for  special  crops,  32;  from 
inadequacy  of  farm  manures,  33 ;  by 
growing  importance  of  fruit-growing, 
34;  will  it  pay  to  use  them,  35;  rea- 
sons for  their  unprofitable  use,  36. 

Artificial  fertilizer  cartridges,  187. 

Ashes.  See  coal,  cotton-hull,  lime- 
kiln, tan-bark  and  wood  ashes. 


Asparagus,  character  of  its  growth, 
264;  conditions  govering  its  sale, 
265;  salt  as  a  fertilizer  for,  266;  fer- 
tilization, 266-8. 

Availability  of  fertilizers.  See  under 
different  fertilizing  materials. 

Azotin,  41. 

Barley,  substitution  of,  for  oats  in 
rotation,  207. 

Barley  and  peas,  fertilization,  248. 

Basic  slag,  70. 

Bat  guano.    See  guano.  [bean. 

Beans,  fertilization,  270.    See  also  soy 

Beets,  character  of  growth,  270;  ferti- 
lization, 271.  See  also  fodder  and 
sugar  beets. 

Berries,  cf ,  fruit  crops  and  small  fruits. 

Blackberries,  fertilization,  302. 

Blood,  dried,  its  characteristics,  40; 
how  obtained,  40;  red,  40;  black, 
41;  its  composition,  41;  the  avail- 
ability of  its  nitrogen,  55. 

Bone-ash,  how  obtained,  66;  its  comi)o- 
sition,  66. 

Bone-black,  how  obtained,  65;  its  com- 
position, 66. 

Bone,  dissolved.    See  superphosphates. 

Bone-meal,  variations  in  its  composi- 
tions, 60;  meaning  of  fine  bone,  61; 
its  best  use  for  soil-improvement 
and  slow-growing  crops,  63,  76;  its 
nitrogen  availability,  55;  its  phos- 
phoric acid  availability,  75 ;  its  phos- 
phate more  useful  than  that  derived 
from  mineral  sources,  66,  73. 

Bone  meal,  raw,  60;  its  comi>osition, 
61 ;  objections  to  its  use,  61. 


(329) 


330 


INDEX 


Bone  meal,  steamed,  61;  its  advan- 
tages, 62;  its  composition,  62. 

Bone  phosphate,  how  to  convert  into 
phosphoric  acid,  134.  See  also  phos- 
phate. 

Bone  tankage,  its  agricultural  value, 
64;  its  composition,  63. 

Brussels  sprouts,  character  of  its 
growth,  272;  fertilization,  273. 

Buckwheat,  fertilization,  323;  as  green 
mannre,  122. 

Cabbage,  character  of  its  growth,  272; 
fertilization,  273. 

Canadian  apatite,  69. 

Carrots,  fertilization,  258. 

Castor  pomace,  its  composition  and 
source,  47;  the  availability  of  its 
phosphoric  acid,  65. 

Cauliflower,  character  of  its  growth, 
272;  fertilization,  273. 

Celery,  character  of  its  growth,  275; 
fertilization,  275. 

Cereals,  character  of  their  growth,  177; 
fertility  content  of,  17;  fertilization, 
191  et  seg.;  as  forage  crops,  241. 

Chemical  elements,  needed  in  plant 
growth,  2;  but  insufficient  by  them- 
selves, 4. 

Cherries,  fertilization,  299. 

Chicken  manure,  its  composition  and 
value,  104. 

Chili  saltpetre.    See  nitrate  of  soda. 

Citrous  fruits,  fertilization,  299. 

Clay  soils,  their  physical  imperfec- 
tions, 171;  usually  need  phosphhoric 
acid  and  lime,  170. 

Climate,  its  influence  on  soil  fertility,  4. 

Clovers,  character  of  their  growth, 
178;  fertilization,  203;  as  forage  crop, 
249;  as  green  mannre,  120;  reQuire 
liberal  supply  of  mineral  elements, 
250. 

Coal  ashes.  111. 

Commercial  valuation  of  fertilizers, 
based  on  commercial  value  of  con- 


stituents, 155 ;  schedule  of  values 
used  in,  157 ;  objections  to,  159 ; 
advantages  of,  161. 

Commercial  value  of  fertilizers,  deter- 
mined by  trade  conditions,  1.53;  no 
measure  of  agricultural  value,  155, 
158;  calculation  of ,  162. 

Corn,  character  of  its  growth,  177, 199; 
fertility  content  of ,  199;  fertilization. 
200 ;  fertilization  for  continuous 
growing,  208. 

Com  forage,  242;  fertilization,  243. 

Com  silage,  fertilization  of  com  for, 
2t4. 

Com,  sweet,  character  of  its  growth, 
276;  fertilization,  276. 

Cotton,  character  of  its  growth,  305: 
its  fertility  content,  307;  fertiliza- 
tion, 307-11 ;  Georgia  and  South  Car- 
olina experiments.  309. 

Cotton-hull  ashes,  112. 

Cotton-seed  meal,  its  composition,  46; 
used  also  as  a  cattle  feed,  46;  its 
nitrogen  availability,  55;  its  phos- 
phoric acid  availability,  65. 

Cow  pea,  character  of  its  growth,  251; 
fertilization,  252 ;  as  forage  crop, 
251 ;  as  green  mannre,  120. 

Crab,  king,  its    composition,  43;     its 

Crimson  clover,  120.  [value,  107. 

Cucumbers,  character  of  tlieir  growtli, 
273;  fertilization,  274,327. 

Currants,  fertilization,  303. 

Denitrifieatiou,      loss       of       fertility 

through,  ]1. 
Dicalcic  phosphoric  acid.    See  reverted 

phosphoric  acid. 
Double  manure  salts.     See  sulfate  of 

potash  and  magnesia. 

Egg-plant,  character  of  its  growth,  277; 

fertilization,  277. 
Experiments  by   the   farmer  himself, 

their  value,  193. 


INDEX 


331 


Farm  labor,  increase  in  cost  of,  31. 

Farm  manures,  losses  in,  19;  inade- 
quate for  demands  of  crops,  33. 

Farm  practice,  irrational,  18. 

Fertility,  what  constitutes  it,  2;  poten- 
tial, 2,  6  ;  practical,  6  ;  dependent 
upon  usable  potential  fertility,  6; 
influenced  by  moisture,  climate,  sea- 
son, physical  character  of  soil,  4,  and 
culture,  10;  loss  of,  by  leaching  8, 
by  drainage  10,  12,  by  denitrification 
11,  by  mechanical  means  13,  by 
removal  of  crops  14;  how  to  reduce 
its  loss,  9. 

Fertility  elements,  prices  received  for 
them  in  different  crops,  15;  contained 
in  milk  16,  wheat  16,  cereals  and 
vegetables  17;  their  usefulness  not 
dependent  upon  their  source,  27. 

Fertilizers,  losses  in,  19;  their  func- 
tion, 21 ;  essential  manurial  elements 
of,  21;  their  indirect  effect,  21,  23; 
their  direct  effect,  23  ;  effect  of  vege- 
table matter  in,  22;  distinction 
between  manures  and,  22 ;  their 
value  depends  upon  availability  of 
essential  constituents,  24;  classifi- 
cation of,  124;  chemical,  126;  com- 
mercial, 124;  high-grade  vs.  low- 
grade,  128,  146;  cf.  artificial  ferti- 
lizers, analysis,  purchase,  use,  and 
valuation  of  fertilizers. 

Fertilizers,  complete, 138;  advantages  of 
purchasing,  140;  disadvantages,  140. 

Fertilizers,  incomplete,  138;  advantages 
of  purchasing,  139;  disadvantages, 139. 

Fertilizers,  mixed,  138;  their  uniform- 
ity, 164;  conditions  influencing  their 
use  and  value,  1G5  et  seq. 

Fertilizer  formulas,  for  cotton,  310; 
fruit  crops,  288;  potatoes,  216,  220, 
221;  sweet  potatoes,  224;  tomatoes, 
233,  234. 

Fertilizing  materials,  standard  or 
high-grade,  125;  low-grade,  124,  127; 
variable  in  composition,  126. 


Fertilizing  systems,  based  upon  spe- 
cific influence  of  a  single  element, 
182;  based  upon  necessity  of  abun- 
dant supply  of  the  minerals, 184;  based 
upon  needs  of  plants  as  shown  by 
chemical  analysis,  186;  where  ferti- 
lizer is  applied  to  money  crop  of 
rotation,  188;  an  irrational  system, 
the  "hit  or  miss,"  189;  in  a  grain  and 
grass  rotation,  198  et  seq.;  fertility 
gained  by  its  use,  204;  system  should 
be  modified  if  no  farm  manures  are 
used,  206. 

Fish,  dried,  its  source,  42;  its  composi- 
tion, 42;  its  nitrogen  availability,  55; 
its  phosphoric  acid  availability,  65. 

Fish  scrap,  crude,  its  composition  and 

Florida  phosphate,  68.  [value,  102. 

Flowers,  fertilization  of,  324. 

Fodder  beets,  fertilization,  258. 

Forage  crops,  cereals  and  grasses,  241; 
clovers  and  other  legumes,  249;  roots 
and  tubers,  257;  conditions  of  growth, 
241;  as  soiling  crops,  254;  New  Jer- 
sey experiments,  249. 

Fruit  crops,  character  of  their  growth, 
181;  require  fertilization,  282;  differ 
from  other  farm  crops,  283;  func- 
tions of  fertilizing  elements  with, 
284;  influence  of  character  of  soil, 
285;  fertilization,  287;  a  basic  for- 
mula for,  288. 

Fruits,  small,  character  of  their 
growth,  300;  fertilization,  301  et  seq. 

Garbage  tankage,  44. 

Gooseberries,  fertilization,  303. 

Grapes,  fertilization,  303. 

Grasses,  character  of  their  growth, 
178;  fertilization,  2C3  et  seq.;  contin- 
uous growing  of,  210;  as  forage  crops, 
241;  for  lawns,  325. 

Greenhouse  crops,  fertilization,  327. 

Green  manures,  meaning  of,  118;  legu- 
minous crops  the  most  valuable  for, 
118;  conditions  influencing  their  use. 


332 


INDEX 


Green  manures,  continued— 
•119;  crops  available  as,  120;  their 
value  dependent  chiefly  upon  their 
nitrogen-gathering  capacity,  118  et 
seg.;  prevent  losses  in  fertility,  122. 
See  alse  forage  crops. 

Guano,  artificial,  inferior  to  the  nat- 
ural product,  48;  bat,  48;  Ichaboe, 
48 ;  Peruvian,  47 ;  phosphatie,  its 
availability,  70,  77. 

Guarantee,  its  necessity,  129;  required 
by  law  in  most  states,  130;  sometimes 
misleading,  133 ;  its  interpretation, 
134  et  seg. 

Gypsum,  its  composition,  115 ;  its 
value,  116. 

Hair  waste,  45,  104. 

Herbaceous  crops,  fertilization,  324. 

Home  mixtures,  their  advantages,  141 ; 
care  required  in  their  preparation, 
141;  formulas,  high-grade  and  low- 
grade,  142  et  seg.;  make-weight  to  be 
avoided,  146. 

Hoof  meal,  its  comi)osition,  42 ;  its 
nitrogen  availability,  55. 

Horn  meal,  its  composition,  45 ;  its 
nitrogen  availability,  55. 

Ichaboe  guano.    See  guano. 

Iron  phosphate ,  70. 

Irrational  farm  practice,  18, 189. 

Kainit,  its  composition,  94;  its  use,  95; 

preferable  to  muriate  of  potash  on 

sweet  potatoes.  225. 
King  crab,  43, 107, 

Lawn  grasses,  fertilization,  325. 

Leather  meal,  45;  its  nitrogen  availa- 
bility, 55. 

Leguminous  crops,  most  valuable  as 
green-manure,  118;  lime  needed  by, 
251.  See  also  clovers,  cow  peas  and 
soy  beans. 


Lemons,  fertilization,  299. 

Lettuce,  character  of  its  growth,  277; 

fertilization,  277,  327. 
Liebig's  organic  chemistry,  etc.,  28. 
Lime,  its  source,  113 ;  its  composition, 

114  ;  quick-lime,  114  ;    marble,  114  ; 

oyster  shell,  114:  gas,  115;  care  needed 

in  its  use,  115;  its  value,  114  et  seg.; 

needed  by  legumes,  254;  its  action  on 

fruit-crops,  285. 
Lime-kiln  ashes,  110. 
Linseed    meal,    its    comiMsition,    46; 

used  also  as  a  cattle-feed,  46. 
Lobster  shells,  108. 
Lucerne.    See  alfalfa. 

Maize.    See  com. 

Make-weight  in  fertilizers,  cost  of 
handling,  146. 

Manures.  See  fertilizers  and  green- 
manures. 

Market-garden  crops,  character  of 
their  growth,  180,  262;  fertilization, 
264 ;  a  basic  fertilizer  for,  267. 

Marl,  its  composition,  112;  soil  im- 
proved by  its  use,  113. 

Meadows,  fertilization,  211. 

Meat,  dried.    See  ammonite. 

Milk,  fertility  content  of,  16. 

Millet,  fertilization,  249;  fertility  con-' 
tent  of,  249. 

Moisture.    See  water. 

Monoealeic  phosphoric  acid.  See  solu- 
ble phosphoric  acid. 

Muck,  its  composition,  106;  used  as  a 
source  of  humus,  106;  how  secured, 
107. 

Muriate  of  ];>otash,  its  composition, 
96;  its  bad  effects  on  tobacco  and 
sugar-beets,  94 ;  how  to  convert  into 
actual  i>otash,  134. 

Muskmelons,  character  of  their  growth, 
273;  fertilization,  274. 

Mussels,  their  comiwsition  and  vaiue, 
107. 

Mustard,  as  a  green-manure,  122. 


INDEX 


333 


Nitrate  of  soda,  its  source,  52;  its  com- 
position and  value,  52 ;  its  availa- 
bility, 53;  compared  with  sulfate 
of  ammonia,  53  ;  how  to  convert 
into  nitrogen,  134;  valuable  as  fer- 
tilizer for  tomatoes,  227. 

Nitrogen,  its  action  on  fruit  crops,  284; 
its  availability  53  et  seq.,  how  esti- 
mated 54,  modified  by  crop  55,  reason 
55,  and  object  of  use  56;  of  the  air 
available  to  leguminosse,  38;  how  to 
convert  into  ammonia,  134;  exists  in 
the  air,  38;  its  different  forms,  25,  39 
etseq.;  its  illusiveness,  8;  important 
because  easily  lost  and  expensive,  8; 
conditions  determining  its  loss,  9; 
loss  by  drainage  10,  by  escape  as 
gas  11,  by  leaching  9;  necessary  for 
plant  growth,  3  ;  nitrate  the  most 
valuable  form,  52;  organic,  39  et  seq.; 
its  availability,  54;  its  sources,  38; 
its  unstability,  8;  how  it  is  used  by 
the  plant,  50,  52. 

Oats,  character  of  its  growth,  177; 
fertilization,  201;  continuous  grow- 
ing of,  209 ;  pouting  period  in  its 
growth,  247. 

Oats  and  peas,  fertilization,  248. 

Oats  forage,  fertilization,  247. 

Onions,  character  of  their  growth,  278; 
fertilization,  280. 

Onion  sets.    See  onions. 

Oranges,  fertilization,  299. 

Organic  nitrogen,  what  it  is,  39;  its 
forms,  40  et  seq.;  its  availability,  54. 

Peaches,  need  and  advantages  of  fer- 
tilization, 294;  methods  of,  297;  New 
Jersey  experiments,  294. 

Peanuts,  fertilization,  324. 

Pears,  fertilization,  291-3. 

Peas,  fertilization,  270 ;  see  also  barley 
and  oats. 

Peat.    See  muck. 

Peruvian  guano.    See  guano. 


Phosphate  of  lime  in  bones,  60. 

Phosphates,  correct  and  false  use  of 
the  term,  58;  animal,  59  et  seq.; 
mineral,  66  et  seq.;  South  Carolina 
rock,  67;  Florida,  68;  Canadian  apa- 
tite, 69;  Tennessee,  69;  iron  70,  its 
availability  76;  how  used  by  plants, 
71;  insoluble  in  water,  72;  useful- 
ness depends  upon  rate  of  decay, 
72;  availability  depends  upon  their 
source  72,  fineness  of  division  73, 
character  of  soil  74,  and  kind  of  crop 
74;  different  from  superphosphates, 
83.    See  also  bone  meal. 

Phosphate  slag,  70. 

Phosphoric  acid,  necessary  for  plant 
growth,  3;  its  loss  through  drainage, 
12;  its  different  forms,  25;  insoluble, 
78;  soluble,  79;  chemically  identical 
independent  of  its  source,  82 ;  re- 
verted 80,  theory  of  its  formation  85, 
its  value  86;  tetra-calcic,  80;  mean- 
ing of  available,  88;  remains  in  soil 
until  removed  by  plants,  90;  its  fixa- 
tion in  the  soil,  91;  how  to  convert 
into  bone-phosphate,  134;  its  action 
on  fruit  crops,  285. 

Pigeon  manure,  49,  105;  its  inferiority 
to  natural  guanos,  49. 

Plant-food,  available,  24;  unavailable, 
34;  necessity  of  adding  more  than  is 
required  by  definite  increase  of  crop, 
205;  loss  from  use  of  soluble,  26; 
cf.  fertilizers. 

Plants,  vary  in  power  of  acquiring 
food,  177. 

Plot  experiments,  scheme  for,  194; 
their  interpretation,  196;  their  value, 
196;  results  of,  197. 

Plums,  fertilization,  299. 

Potash,  necessary  for  plant  growth,  3; 
its  loss  through  drain  nge,  12;  its  dif- 
ferent forms,  25,  93 ;  its  importance, 
92;  importance  of  form,  93;  its  fixa- 
tion in  the  soil,  98;  how  to  convert 
actual  into  muriate  and  sulfate,  134; 


334 


INDEX 


Potash,  continued- 
its  action  on  fruit  crops,  284 ;    see 
also   kainit,    sylvinit,   muriate   and 
sulfate  of  potash. 

Potash  salts,  their  occnirence,  92;  their 
uniformity  of  price,  92. 

Potatoes,  fertility  content  of,  215;  fer- 
tilization for  early,  215  et  seq.;  fer- 
tilization for  late,  220 ;  sulfate  of 
potash  improves  their  quality,  219; 
importance  of  form  of  fertilizing 
elements,  219;  New  York  (Geneva) 
experiments,  215,  218. 

Poultry  manure,  49,  104;  its  composi- 
tion, 104. 

Powder  waste,  117. 

Pumpkins,  character  of  their  growth, 
273 ;  fertilization,  274. 

Purchase  of  fertilizers,  the  unit  basis 

128,  its  advantages  129;  the  ton  basis, 

129,  its  defects,  129 ;  law  not  sufiBcient 
for  protection,  130;  intelligonce 
needed,  131;  cooperative,  148;  meth- 
ods of  138,  by  buying  raw  materials 
138,  by  buying  mixed  brands  138, 
advantages  and  disadvantages  of 
each  method,  138. 

Rape,  fertilization,  260. 

Raspberries,  fertilization,  302. 

Rhubarb,  character  of  its  growth,  277; 
fertilization,  278. 

Root  crops,  character  of  their  growth, 
179;  fertility  content  of,  258;  ferti 
lization,  258. 

Roses,  fertilization,  324. 

Rye,  as  green  manure,  122;  as  substi- 
tute for  wheat  in  rotation,  207 ;  fertili- 
zation for  continuous  growing,  209. 

Rye  forage,  fertilization,  245,  246. 

Sandy  soils,  their  physical  imi)erfec- 
tions,  170;  usually  need  potash,  170. 

Scallions,  character  of  their  growth, 
279;  fertilization,  280. 

Season,  its  influence  on  soil  fertility,  4. 


Sea  weed,  108. 

Sewage,  its  composition  and  value,  105. 

Soda,  nitrate  of.    See  nitrate. 

Soil  fertility,  its  importance,  1;  what 
constitutes,  1;  influenced  by  moist- 
ure, climate  and  season,  4;  qualified 
by  location  of  soil,  5. 

Soiling  crops,  scheme  for,  255;  New 
Jersey  experiments,  256. 

Soils,  influence  of  physical  character 
of,  4;  their  derivation  a  guide  as  to 
deficiencies,  168.  See  clay  and  sandy 
soils. 

Sorghum,  fertilization,  when  grown  for 
forage  and  for  sugar,  322. 

South  Carolina  rock.  See  phosphate 
and  sui)erphosphate. 

Soy  bean,  as  forage  crop,  120,  251; 
character  of  its  growth,  251 ;  fer- 
tilization, 251. 

Spinach,  character  of  its  growth,  277; 
fertilization,  277. 

Sprouts.    See  Brussels  sprouts. 

Squashes,  character  of  their  growth, 
273 ;  fertilization,  274. 

Strawberries,  fertilization,  301. 

Sugar-beets,  fertility  content  of,  236 ; 
fertilization  when  grown  for  sugar 
237,  when  grown  for  fodder,  2.58 ; 
effect  of  previous  deep  cultivation 
on,  239. 

Sugar-cane,  fertility  content  of,  318; 
fertilization,  318;  Louisiana  exiwri- 
ments,  317. 

Sulfate  of  ammonia,  its  composition, 
51;  its  source,  51;  advantages  of  its 
use,  51 ;  its  availability,  53 ;  com- 
pared with  nitrate  of  soda,  53;  how 
to  convert  into  nitrogen,  134. 

Sulfate  of  lime.    See  gypsum. 

Sulfate  of  potash,  its  composition,  97; 
preferable  to  muriate  for  some  crops, 
94,  219;  how  to  convert  into  actual 
potash,  134. 

Sulfate  of  potash  and  magnesia,  its 
composition,  97. 


INDEX 


335 


Superphosphates,  how  made,  80;  dif- 
ferences due  to  source,  81,  83 ;  differ- 
ent from  phosphates,  83;  bone,  83, 
88;  mineral,  84,  88;  double,  87,  89; 
their  composition,  88 ;  bone-black, 
88  ;  South  Carolina  rock,  88 ;  Florida, 
89;  Tennessee,  89 ;  should  contain  no 
free  acid,  89. 

Swedes,  fertilization,  260. 

Sweet  potatoes,  quality  an  important 
factor  in,  221 ;  fertility  content  of, 
222;  fertilization,  222  e<  «e(7.;  Georgia 
experiments,  223  ;  New  Jersey  experi- 
ments, 223,  226. 

Sylvinit,  its  composition,  95 ;  its  use, 
96. 

Tan-bark  ashes,  their  composition,  110. 

Tankage,  its  source,  43 ;  its  composi- 
tion, 44  ;  concentrated,  43 ;  its  varia- 
bility, 44;  its  nitrogen  availability,  55; 
see  also  bone  and  garbage  tankage. 

Tennessee  phosphate.    See  phosphate. 

Tetra-calcie  phosphoric  acid.  See 
phosphoric  acid. 

Thomas  phosphate  meal.  See  iron 
phosphate. 

Timothy,  character  of  its  growth,  178; 
fertilization,  203. 

Tobacco,  fertility  content  of,  312; 
effect  of  fertilizers  on  quality,  312; 
injurious  effect  of  chlorids,  315  ;  fer- 
tilization, 313  et  seq.;  Connecticut 
experiments,  313. 

Tobacco  stems,  their  composition,  100 ; 
their  value,  101. 

Tomatoes,  fertilization  for  early,  227, 
for  late,  231 ;  composition  of  vine, 
233;     composition     of     fruit,     233; 


nitrate  of  soda  as  fertilizer  for,  227, 
235  ;  New  Jersey  experiments,  226. 

Tri-calcic  phosphoric  acid.  See  insolu- 
ble phosphoric  acid. 

Tuber  crops,  for  forage,  261. 

Turnips,  fertilization,  260,  271 ;  chasr 
aeter  of  their  growth,  270. 

Unit  system  of  purchase,  128. 

Use  of  fertilizers,  object  of,  167; 
conditions  modifying,  167  et  seq.; 
knowledge  of  nature  of  soil  neces- 
sary in,  170 ;  influence  of  previous 
treatment  and  cropping  on,  172 ; 
influence  of  character  of  crop,  175 ; 
influence  of  method  of  farming,  176 ; 
importance  of  system  in,  198. 

Valuation  of  fertilizers.  See  Commer- 
cial valuation. 

Vegetable  matter  in  manures,  its  effect 
on  physical  character  and  absorptive 
power  of  soils,  22. 

Vegetables,  fertility  content  of,  17. 

Ville's  system  of  fertilization,  182. 

Waste  from  phosphorus  works,  116. 

Water,  its  influence  on  soil  fertility,  4. 

Watermelons,  character  of  their 
growth,  273  ;  fertilization,  274. 

Wheat,  fertility  content  of,  16,  192; 
character  of  its  growth,  177 ;  fer- 
tilization 202,  for  continuous  grow- 
ing of,  208. 

Wheat  forage,  fertilization,  245. 

Wood  ashes,  their  composition,  109; 
valuable  source  of  potash,  110. 

Wood  waste,  45 ;  its  composition,  103; 
its  nitrogen  availability,  55. 


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T 


WORKS    BY    PROFESSOR     BAILEY 

HE  EVOLUTION  OF  OUR  NA- 
TIVE FRUITS.  By  L.  H.  BAILEY,  Pro- 
fessor  of  Horticulture  in  the  Cornell  University. 

471  PACES  — 12B  ILLUSTRATIONS  — SZ.OO 

In  this  entertaining  volume,  the  origin  and  de- 
velopment of  the  fruits  peculiar  to  North  America 
are  inquired  into,  and  the  personality  of  those  horti- 
cultural pioneers  whose  almost  forgotten  labors 
have  given  us  our  most  valuable  fruits  is  touched 
upon.  There  has  been  careful  research  into  the 
history  of  the  various  fruits,  including  inspection 
of  the  records  of  the  great  European  botanists  who 
have  given  attention  to  American  economic  botany. 
The  conclusions  reached,  the  information  presented, 
and  the  suggestions  as  to  future  developments,  can- 
not but  be  valuable  to  any  thoughtful  fruit-grower, 
while  the  terse  style  of  the  author  is  at  its  best  in 
his  treatment  of  the  subject. 

The  Evolution  of  our  Native  Fbuits  discusses  The  Rise  of 
the  American  Grape  (North  America  a  Natural  Vineland,  Attempts 
to  Cultivate  the  European  Grape,  The  Experiments  of  the  Dufours, 
The  Branch  of  Promise,  John  Adiura  and  the  Catawba,  Rise  of 
Commercial  Viticulture,  Why  Did  the  Early  Vine  Experiments  Fail  1 
Synopsis  of  the  American  Grapes) ;  The  Strange  History  of  the  Mul- 
berries (The  Early  Silk  Industry,  The  "Multicaulis  Craze,") ;  Evolu- 
tion of  American  Plums  and  Cherries  (Native  Plums  in  General, 
The  Chickasaw,  Hortulana,  Marianna  and  Beach  Plum  Groups, 
Pacific  Coast  Plum,  Various  Other  Types  of  Plums,  Native  Cherries, 
Dwarf  Cherry  Group ) ;  Native  Apples  (Indigenous  Species,  Amelio- 
ration has  begun);  Origin  of  American  Raspberry-growing  (Early 
American  History,  Present  Types,  Outlying  Types) ;  Evolution  of 
Blackberry  and  Dewberry  Culture  (The  High-bush  Blackberry  and 
Its  Kin,  The  Dewberries,  Botanical  Names);  Various  Types  of 
Berry-like  Fruits  (The  Gooseberry,  Native  Currants,  Juneberry, 
Buffalo  Berry,  Elderberry,  High-bush  Cranberry,  Cranberry,  Straw- 
berry); Various  Tjrpes  of  Tree  Fruits  (Persimmon,  Custard-Apple 
Tribe,  Thom-Apples,  Nut-Fruits) ;  General  Remarks  on  the  Improve- 
ment of  our  Native  Fruits  (What  Has  Been  Done,  What  Probably 
Should  Be  Done). 


T 


WORKS    BY  PROFESSOR    BAILEY 

HE  SURVIVAL  OF  THE  UNLIKE: 

A  Collection  of  Evolution  Essays  Suggested 

by  the  Study  of  Domestic  Plants.  By  L.  H. 
BAILEY,  Professor  of  Horticulture  in  the  Cornell 
University. 

FOURTH  EDITION  — 815    PACES  —  22    ILLUSTRATIONS— $2.00 

To  those  interested  in  the  underlying  philosophy 
of  plant  life,  this  volume,  written  in  a  most  enter- 
taining style,  and  fully  illustrated,  will  prove  wel- 
come. It  treats  of  the  modification  of  plants  under 
cultivation  upon  the  evolution  theory,  and  its  atti- 
tude on  this  interesting  subject  is  characterized 
by  the  author's  well-known  originality  and  inde- 
pendence of  thought.  Incidentally,  there  is  stated 
much  that  will  be  valuable  and  suggestive  to  the 
working  horticulturist,  as  well  as  to  the  man  or 
woman  impelled  by  a  love  of  nature  to  horticul- 
tural pursuits.  It  may  well  be  called,  indeed,  a 
philosophy  of  horticulture,  in  which  all  interested 
may   find  inspiration  and  instruction. 

The  Survival  of  the  Unlike  comprises  thirty  essays  touching 
■upon  The  General  Fact  and  Philosophy  of  Evolution  (The  Plant 
Individual,  Experimental  Evolution,  Coxey's  Army  and  the  Russian 
Thistle,  Recent  Progress,  etc.);  Expounding  the  Fact  and  Causes  of 
V^ariation  (The  Supposed  Correlations  of  Quality  in  Fruits,  Natural 
History  of  Synonyms,  Reflective  Impressions,  Relation  of  Seed- 
bearing  to  Cultivation,  Variation  after  Birth,  Relation  between 
American  and  Eastern  Asian  Fruits,  Horticultural  Geography,  Prob- 
lems of  Climate  and  Plants,  American  Fruits,  Acclimatization,  Sex 
in  Fruits,  Novelties,  Promising  Varieties,  etc. ) ;  and  Tracing  the 
Evolution  of  Particular  Types  of  Plants  (the  Cultivated  Strawberry, 
Battl«  of  the  Plums,  Grapes,  Progress  of  the  Carnation.  Petunia. 
The  Garden  Tomato,  etc.). 


CYCLOPEDIA  or 
A\1ERICAN  HORTICLLTURE 

COMPRISING  DIRECTIONS  FOR  THE  CULTIVATION  OF  HORTICULTURAL 
CROPS,  AND  ORIGINAL  DESCRIPTIONS  OF  ALL  THE  SPECIES  OF 
FRUITS,  VEGETABLES,  FLOWERS  AND  ORNAMENTAL  PLANTS  KNOWN 
TO    BE    IN    THE    MARKET    IN    THE    UNITED    STATES     AND    CANADA 

By  L.  H.  bailey 

ASSISTED  BY  MANY  EXPERT  CULTIVATORS  AND  BOTANISTS 

In  Four  Quarto  Volumes, 
lllostrated  with  over  Two  Thousand  Original  Engravings 

THIS  monumental  work,  the  most  comprehensive 
review  of  the  vegetable  world  yet  made  by  an 
American,  is  now  in  the  press.  Though  distinctly 
an  American  work,  not  only  plants  indigenous  to 
the  North  American  continent  are  mentioned,  but 
also  all  the  species  known  to  be  in  the  horticul- 
tural trade  in  North  America,  of  whatever  origin. 
It  is  really  a  survey  of  the  cultivated  plants  of  the 
world. 

The  Editor,  Professor  L.  H.  Bailey,  has  been 
gathering  material  for  this  Cyclopedia  for  many 
years.  He  has  enlisted  the  cooperation  of  many 
men  of  attainments,  either  in  science  or  practice, 
and  the  Cyclopedia  has  the  unique  distinction  of 
presenting  for  the  first  time,  in  a  carefully  arranged 
and  perfectly  accessible  form,  the  best  knowledge  of 
the  best  specialists  in  America  upon  gardening, 
fruit-growing,  vegetable  culture,  forestry,  and  the 


like,  as  well  as  exact  botanical  information.  It  is 
all  fresh,  and  not  a  rehash  of  old  material.  No 
precedent  has  been  followed ;  the  work  is  upon  its 
own  original  plan. 

Many  scientific  botanical  authors  of  justly  high 
repute*  decline  to  give  attention  to  the  important 
characters  of  cultivated  plants,  confining  their  work 
to  the  species  in  the  original  forms  only.  Pro- 
fessor Bailey  takes  the  view  that  a  subject  of  com- 
mercial importance,  one  which  engages  the  attention 
and  affects  the  livelihood  of  thousands  of  bright 
people,  is  decidedly  worthy  the  investigation  of  the 
trained  botanist.  In  the  Cyclopedia  of  American 
Horticulture,  therefore,  very  full  accounts  are  given 
of  the  botanical  features  of  all  important  commercial 
plants,  as  the  apple,  cabbage,  rose,  etc.  At  the  same 
time,  practical  cultivators  submit  observations  upon 
culture,  marketing,  and  the  like,  and  frequently  two 
opinions  are  presented  upon  the  same  subject  from 
different  localities,  so  that  the  reader  may  have 
before  him  not  only  complete  botanical  information, 
but  very  fully  the  best  practice  in  the  most  favor- 
able localities  for  the  perfection  of  any  fruit  or 
vegetable  or  economic  plant. 

ILLUSTRATIONS 

The  pictorial  character  of  the  work  is  likewise  nota- 
ble. There  are  nearly  three  thousand  illustrations, 
and  they  are  made  expressly  for  this  work,  either 
from  accurate  photographs  or  from  the  specimens. 
These  illustrations  have  been   drawn  by   competent 


horticultural  artists,  in  nearly  every  case  under  iht 
eye  of  the  Editor,  or  with  the  supervision  of  some 
one  of  the  sub -editors.     No  "trade"  cuts  are  used. 

[n  planning  the  illustrations,  artistic  effect  has 
been  kept  in  view,  and  while  no  drawing  is  used 
which  does  not  show  its  subject  with  perfect  scien- 
tific accuracy,  the  monotonous  so-called  "botanical" 
outlines,  often  made  from  lifeless  herbarium  speci- 
mens, are  notably  absent.  The  intention  is  to  show 
the  life  of  the  plant,  not  merely  its  skeleton. 

CONTRIBITORS,  SYSTEM,  ETC. 

As  above  mentioned,  the  contributors  are  men 
eminent  as  cultivators  or  as  specialists  in  the  various 
subjects.  The  important  articles  are  signed,  and  it 
is  expected  that  the  complete  work  will  include  fully 
5,000  signed  contributions  by  horticulturists,  culti- 
vators and  botanists. 

The  arrangement  is  alphabetical  as  to  the  genera, 
but  systematic  in  the  species.  A  very  simple  but 
complete  plan  of  key-letters  is  used,  and  the  whole 
arrangement  is  toward  ease  of  reference  as  well  as 
completeness  of  information.  To  each  large  genus 
there  is  a  separate  alphabetic  index. 

Important  commercial  subjects  are  treated  usually 
under  the  best  known  name,  whether  it  be  the 
scientific  or  "common"  designation.  Thus,  the  apple 
is  fully  discussed  as  apple,  rather  than  as  Pyrus 
Malus,  and  the  carnation  comes  into  view  in  the 
third  letter  of  the  alphabet,  not  as  Dianthus  Garyo- 
phyllus.     Carefully  edited   cross-references   make   it 


easy  to  find  any  desired  subject,  however,  in  the 
shortest  time. 

The  plan  of  presenting  the  full  details  of  cul- 
ture of  important  plants,  through  the  views  of 
acknowledged  practical  experts  upon  the  various 
subjects,  assures  the  great  value  of  the  book  to  the 
man  or  woman  who  is  obtaining  a  living  from 
horticultural  pursuits. 

A  special  feature  of  the  Cyclopedia  of  American 
Horticulture  is  its  wealth  of  bibliographic  reference. 
The  world's  horticultural  literature  has  been  thor- 
oughly searched,  and  most  carefully  indexed,  so  that 
the  student  will  find  citations  to  nearly  every  avail- 
able article  or  illustration  upon  any  subject  consulted. 

DETAILS  OF  PIBLICATION 

The  Cyclopedia  of  American  Horticulture  is  to 
be  completed  in  four  handsome  quarto  volumes, 
embracing  about  two  thousand  pages,  with  more 
than  that  number  of  original  illustrations.  It  is 
carefully  printed  upon  specially  made  paper  of  a 
permanent  character.  Vol.  I  (A  to  D,  509  pages, 
743  illustrations,  9  plates),  Vol.  II  (E  to  M,  544 
pages,  710  illustrations,  10  plates),  and  Vol.  Ill  (N 
to  Q,  432  pages,  606  illustrations,  11  plates)  are  now 
ready,  nnd  the  last  volume  is  in  press. 

The  work  is  sold  only  by  subscription,  and 
orders  will  be  accepted  for  the  full  set  only. 
Terms  and  further  information  may  be  had  of 
the  Publishers, 

THE    MACMILLAN    COMPANY 

No.  66  Fifth  Avenue  NEW   YORK 


WORKS    BY    PROFESSOR    BAILEY 

ESSONS  WITH  PLANTS:  Sugges- 
tions for  Seeing  and  Interpreting  Some  of 
the  Common   Forms  of  Vegetation.     By  l. 

H.  BAILEY,  Professor  of  Horticulture  in  the  Cornell 
University,  with  delineations  from  nature  by  W.  S. 
HOLDSWORTH,  of  the  Agricultural  College  of 
Michigan. 

SECOND  EDITION— 481  PACES— 446  ILLUSTRATIONS— 12  MO- 
CLOTH— SI.  10  NET 

There  are  two  ways  of  loading  at  nature.  The 
old  way,  which  you  have  found  so  unsatisfactory, 
was  to  classify  everything — to  consider  leaves,  roots, 
and  whole  plants  as  formal  herbarium  specimens, 
forgetting  that  each  had  its  own  story  of  growth 
and  development,  struggle  and  success,  to  tell. 
Nothing  stifles  a  natural  love  for  plants  more  effect- 
ually than  that  old  way. 

The  new  way  is  to  watch  the  life  of  every  grow- 
ing thing,  to  look  upon  each  plant  as  a  living 
creature,  whose  life  is  a  story  as  fascinating  as  the 
story  of  any  favorite  hero.  "Lessons  with  Plants" 
is  a  book  of  stories,  or  rather,  a  book  of  plays,  for 
we  can  see  each  chapter  acted  out  if  we  take  the 
trouble  to  look  at  the  actors. 

"I  have  spent  some  time  in  most  delightful  examination  of  it,  and  the 
longer  I  look,  the  better  I  like  it.  I  find  it  not  only  full  of  interest,  but 
eminently  suggestive.  I  know  of  no  book  which  begins  to  do  so  much  to 
open  the  eyes  of  the  student —whether  pupil  or  teacher  — to  the  wealth  of 
meaning  contained  in  simple  plant  forms.  Above  all  else,  it  seems  to  be 
full  of  suggestions  that  help  one  to  learn  the  language  of  plants,  so  they 
may  talk  to  him."—  Darwin  L.  Bardwell,  Superintendent  of  Schools,  Bing- 
hainton. 

"It  is  an  admirable  book,  and  cannot  fail  both  to  awaken  interest  in 
the  subject,  and  to  serve  as  a  helpful  and  reliable  guide  to  young  students 
of  plant  life.  It  will,  I  think,  fill  an  important  place  in  secondary  schools, 
and  comes  at  an  opportune  time,  when  helps  of  this  kind  are  needed  and 
eagerly  sought."- Professor  V.  M.  Spai.dino,  University  of  Michigan. 

FIRST    LESSONS   WITH    PLANTS 

An  Abridgement  of  the  above.  117  pages — 116  illustra- 
tions— 40  cents  net. 


UCSB  LIBRARY 


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